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TEMPEST, SCIF, and Electronic Shielded Enclosures

For systems to be certified to TEMPEST (Telecommunications Electronics Material Protected from Emanating Spurious Transmissions) specific test standards need to be passed such as NSA No. 94-106 for shielded enclosures and other NSA standards depending on the intended environment and operation. The TEMPEST certified telecommunications electronic enclosure needs to be a “Faraday Cage”. A Faraday Cage is an enclosure made of electrically conductive materials capable of blocking magnetic and electric fields, commonly known as the electromagnetic field, see Figure #1.

Figure 1 Electric and Magnetic Field

Figure 1 – Electric and Magnetic Field
(courtesy of HyperPhysics)

Figure 2 Shielded Electronic Enclosures

Figure 2 – Shielded Electronic Enclosures
(courtesy of Milium Textiles and Vertex Structures)

Figure 3 Shielded Tent

Figure 3 – Shielded Tent
(courtesy of Select Fabricators)

Figure 4 SCIF Shielded Information Facilities

Figure 4 – SCIF Shielded Information Facilities
(courtesy of Armag)


Faraday Cages come in all sort of sizes and configurations. A typical Faraday Cage is an electromagnetic shielded enclosure usually constructed or lined with metal, Figure #2. A variation of a typical shielded enclosure is a shielded tent constructed of electrically conductive fabric, Figure #3. In addition to being conductive, a shielded enclosure also needs to incorporate shielding products such as: honeycomb vent panels for airflow, conductive windows for viewing, and conductive gaskets for access doors, connectors, antenna mounts, power/signal entry panels, etc…. Power and signal lines entering the shielded enclosure also need to be electromagnetically filtered to prevent unwanted conducted emissions. Internal to the shielded enclosure structural seams between the floor and wall, wall to ceiling, and all corner seams need to be electromagnetically sealed either by welding, conductive gaskets, or conductive caulk. At this point, from the need of all the shielding products, you might have realized that the principle of a shielded enclosure is to provide a complete low impedance path by addressing all entry, exit, and structural apertures. Shielding products therefore provide an electrically conductive, low impedance, path allowing the electromagnetic field to propagate on the outer surface of the shielded enclosure or on the inner surface if the electromagnetic field is generated from electronic equipment within the shielded enclosure. Therefore, shielding of an enclosure enables the internal electronic systems to be less susceptible to outside radiated emissions and covert to outside radio receivers and other detectors attempting to receive information.

An example of a shielded enclosure that generates internal electromagnetic fields that carry confidential information is a SCIF (Sensitive Compartmented Information Facility), Figure #4. A SCIF is a shielded enclosure used to process “Sensitive Compartmented Information (SCI)” material. SCIF shielded enclosures are used for U.S. Intelligence worldwide for classified information concerning intelligence sources, methods, or analytical processes; the information and material must be treated with correct classification and be protected.

Faraday Cages such as SCIF, conductive tents, and manned or unmanned electronic system enclosures require shielding products to meet TEMPEST and other military EMC (electromagnetic compatibility) specifications. As previously mentioned, these specialized conductive shielding products enable ventilation Figure #5, viewing Figure #6, and conductive gaskets for entry/exit doors, connector panels, structural seams, power and signal entry panels, etc…, Figure #7; in addition to power and signal filtration Figure #8.

Figure 5 Honeycomb Ventilation Panels

Figure 5 – Honeycomb Ventilation Panels
(courtesy of MAJR Products Corp.)

Figure 6 Conductive Windows

Figure 6 – Conductive Windows
(courtesy of MAJR Products Corp.)

Figure 7 EMI/RFI gasket products

Figure 7 – EMI/RFI gasket products
(courtesy of MAJR Products Corp.)

Figure 8 EMI/RFI filters

Figure 8 – EMI/RFI filters
(courtesy of Corry Micronics Inc.)

EMI Gaskets: Die-Cut, Water Jet & Flash Cutting

EMI gaskets are used in a variety of electronic devices where EMI/RFI is an issue including communications, military electronics, and RF applications.

When it comes to manufacturing EMI gaskets, there are three different methods MAJR Products uses:

1. Die-Cut
2. Water Jet
3. Flash Cutting

Each of these three manufacturing techniques have specific benefits associated with them and are best suited for a plethora of different products and materials including:

  • Conductive materials
  • Rubber
  • Cork
  • Foils
  • Silicones
  • Neoprenes
  • Porons
  • Thermal Materials
  • Tapes
  • Thin Films
  • Mylar
  • Kapton

1. Die-Cut

Die-cutting is a high-speed method of using a die to shear webs of low-strength materials in order to mass produce a wide range of industrial products, including gaskets. MAJR creates a predesigned steel rule die of the item, and then uses a press to replicate the item with the chosen material.

Benefits of the Die-Cut Method

  • Cost effective.
  • Good for high-volume orders.
  • Allows tight tolerances and accuracy.
  • Ability to manufacture gasket configurations of any shape or size.
  • It can handle a variety of different materials for manufacturing gaskets, including:

Items Typically Created via the Die-Cut Method

  • Gaskets
  • Washers
  • Insulating foam
  • Vehicle parts

2. Water Jet

The water jet process of creating items, including gaskets, involves high pressure water that is forced through a small nozzle (0.010″ to 0.015″ in diameter) to produce a very precise cut of the material.

Benefits of the Water Jet Method

  • Gaskets can be tightly nestled.
  • Cuts are extremely accurate.
  • A good method for complex and intricate parts.
  • Provides an efficient use of raw materials.
  • Less chance of compression distortion.
  • Works well for producing prototypes and other test parts.
  • A great method for short production runs.
  • Very clean process because you are only using water.

Items Typically Created Via the Water Jet Method

  • Gaskets
  • Textiles
  • Rubber
  • Foam
  • Plastics
  • Composites
  • Metal

3. Flash Cutting

If the gaskets you need require thicknesses from .001” to .75” with tight tolerances MAJR utilizes the flash cutting method. The flash cutting method requires the use of a CNC machine that holds a blade in place to accurately and cleanly cut through the production material. Flash cutting results in a product with exact and precise measurements. Flash cutting also allows us to produce prototypes from CAD or PDF files.

Benefits of Flash Cutting

  • Allows for many customization options.
  • Can hold tolerances to .005”
  • Offers the fastest production turn-around time.
  • Exceptional for high volume applications.
  • The best method for projects where product aesthetics are important.
  • Does not cause concavity.
  • Produces clean edges.
  • Excellent for projects that require rapid prototyping.
  • Can utilize a variety of materials with the flash cut method.
  • Can be more cost-effective than jet cutting and die-cutting.

Items Typically Created via Flash Cutting

  • Gaskets
  • Soft plastics
  • Rubber
  • Laminated materials
  • Foam
  • Industrial fabrics
  • Technical textiles
  • Paper

MAJR Products Would Love To Take Care Of Your EMI Gasket Needs!

MAJR Products is an internationally recognized manufacturing leader of EMI/RFI shielding products, including gaskets. We have been serving the electronics industry by providing electromagnetic interference shielding products and solutions to some of the largest defense contractors in the country for close to 25 years.

We offer a wide variety of EMI gaskets, including:

  • EMI Connector Gaskets
  • Shield Seal Strip EMI Gaskets
  • Wire Mesh Gaskets
  • Custom Die-Cut Shielding Gaskets
  • Custom Molded Gaskets
  • Custom O-Ring Gaskets
  • Metallized Fabric Shielding EMI Gaskets
  • Fingerstock Gaskets
  • Rigid Mount Frame EMI Gaskets
  • Mesh Over Elastomer EMI Gaskets

To request a quote, fill out our simple form, and one of our representatives will be in touch with you shortly. You can also request samples of our many top-notch products.


MAJR Products and Raytheon

MAJR Products Is Now A Raytheon Company Approved Supplier for Welding

MAJR Products is proud to announce that we are a recent addition to the Raytheon Company Approved Supplier List for welding products. 

This approval formalizes the existing relationship between MAJR Products, Raytheon, and its various partners. This fruitful partnership will allow MAJR Products to expand the scope of our services and the industries we serve. We are very excited about this opportunity. 

About Raytheon

Raytheon is a technology and innovation leader specializing in defense, civil, and cybersecurity markets around the world. This prestigious company strives to provide the maximum practical opportunity for many diverse businesses, including small businesses and veteran-owned companies, like MAJR Products. 

About MAJR Products

MAJR Products is an internationally recognized manufacturing leader of EMI/RFI shielding products. We have been serving the overall electronics industry by providing electromagnetic interference shielding products and solutions to some of the largest defense contractors in the country for close to 25 years. 

Some of the many products we offer include:

  • Radio frequency shielding gaskets
  • Gaskets for connectors
  • EMI/RFI ventilation panels and filters
  • Shielded fan vents 
  • EMI windows
  • Welding products


Get In Touch With Us!

We’d love to work with you on your next project! To request a quote, fill out our simple form and one of our representatives will be in touch with you shortly.


MAJR Products To Sponsor 2019 SAE G46 EMC Meeting At The IEEE EMC Symposium

The internationally recognized manufacturing leader of EMI/RFI shielding products, MAJR Products, will be sponsoring the SAE G46 EMC Meeting at the 2019 International Symposium on Electromagnetic Compatibility, Signal & Power Integrity, in New Orleans, Louisiana.

About The 2019 IEEE EMC Symposium

Also known as the IEEE EMC Annual Symposia, the IEEE EMC Symposium, the IEEE International Symposium, and the IEEE International Symposium on EMC+SIPI, this conference is the must-attend event of the year for EMC and SIPI professionals from all over the world who are interested in learning more about electromagnetic compatibility as well as signal and power integrity techniques. This year’s IEEE EMC Symposium will run from Monday, July 22nd through Friday, July 26th.

Attendees of the IEEE EMC Annual Symposia will receive five full days of training in the form of innovative sessions, interactive workshops, tutorials, experiments, and demonstrations. There will also be ample opportunities for social networking and making connections with other professionals in the industry.

The SAE G46 EMC Meeting

The MAJR Products team will be sponsoring the SAE G46 EMC Meeting at this year’s IEEE EMC Symposium, which will take place on Tuesday, July 23, 2019. We are very excited for the opportunity to work with the IEEE Electromagnetic Compatibility Society and to be a part of this fantastic event that is dedicated to providing education, tools, and techniques for reducing electromagnetic interference. It’s always an honor to be amongst industry professionals.

About MAJR Products

MAJR Products is a veteran-owned business and internationally recognized manufacturing leader of EMI/RFI shielding products. We have over 25 years of experience working with EMI/RFI shielding materials and their respective applications and are proudly ISO 9001:2008 and ITAR Registered. Learn more about MAJR and the variety of high-quality EMI/RFI products and services we provide.

Knitted Wire Mesh EMI/RFI Shielding Tape (1000 series)

Keeping emitting sources and radiating paths under control with EMI Shielding Tape

In simple terms, radiated EMI emission starts from an emitting source, propagates via a radiating path and reaches a susceptible receiver. The strength of the radiated EMI is determined by the source, the media surrounding the source and the distance between the source and the susceptor1…unless there are cables in close proximity to the source or receptor, in which case all bets are off. In that case you need EMI shielding tape.

Electronic or electrical cables can compound EMI noise problems as they are major transmitter of stray signals. Unshielded cables can act as a conductor, sending direct disruption to sensitive equipment. They can also act like an antenna, spreading RF noise throughout a hardened enclosure. But they also act like a receptor, picking up stray EMI from other places. The best way to keep those signals contained along cabling is with EMI shielding tape.

Knitted Wire Mesh EMI/RFI Shielding Tape (1000 series)EMI shielding tape is a knitted circular strip of wire mesh that resembles a gauze tube or elongated wire stocking. It’s construction is perfect for wrapping cables where conformity is needed without adding a lot of weight or bulk. It’s flexibility characteristics make it more suitable than foil tape where cables twist or bend. Using the appropriate diameter EMI shielding tape to fit the application, cables are covered in an over-wrap fashion to avoid gaps and achieve attenuation. The wrap can then be grounded at one or both ends.

Besides coming in various diameters ranging from .437” to 5.5” to form numerous possible widths for the wrap, MAJR Products offers knitted wire mesh tape in variety of metal wires. Our Sn/Cu/Fe wire, in accordance with ASTM B-520, provides 3% tin for low impedance and maximum corrosion resistance, 40% copper for maximum conductivity and 54% steel for strength and permeability. It offers superior performance characteristics in terms of pull strength (50 lbs) and elongation (100 percent). RFI/EMI shielding tape is also available in monel and aluminum wires, allowing you to choose the right material for your application without needlessly over-spending. Very few of our competitors can offer so many choices in terms of tape diameter and the material used.

Don’t let those electrical or electronic cables and harnesses become a raceway for EMI noise or an antenna for picking up and broadcasting stray signals. Overbraiding with EMI shielding mesh tape is the easiest and most cost effective way to achieve the attenuation needed for a hardened enclosure.

You can find more technical details and a spec download on a page devoted to knitted wire mesh tape on our website, where you can request free samples. You can also call or message our our engineers if you have questions about metal wire choices, proper diameters or the required overlap for your application.

1Xingcun Colin Tong, Advanced Materials and Design for EMI Shielding, CRC Press, Taylor and Francis Group, 2009. Chapter “Radiated EMI Emission”, pg. 6.

Emi shielding materials special uses and applications.

MAJRabsorber™ : The Latest Innovation in RF Absorber Material and Changing How we Think About What is Possible

Every once in awhile true innovation transforms an industry.  Consider what the cloud has meant for business as it brought about data storage, access and co-worker collaboration.  Look at how the Internet of Things is frontiering cashierless shopping. Such champions in innovation will not only make the industry and applications they integrate with faster, easier or better, they change the way we think about what’s possible.  Over time these disruptors soon become the new industry standard and we wonder how we lived without them before their introduction. For the EMI/RFI shielding industry, this transformative shift is now taking place in RF absorber materials with MAJR Products’ new MAJRabsorber™.

MAJRabsorber™’s Innovative layered Construction

New rf absorber from MAJR Products for EMI shielding.MAJRabsorber™ not only absorbs and dissipates but reflects stray noise. Within frequencies of 1 – 18 GHz it offers attenuation levels which greatly surpass other absorber materials on the market and, in fact, within many frequencies attenuation is more than doubled.  It achieves its effectiveness because of its “layered” construction. It has a flexible, inner conductive layer that is placed between two non-conductive layers, allowing MAJRabsorber™ to reflect stray signals radiated emissions and affiliated currents gathered by the electromagnetically reflective inner layer back through the non-conductive RF absorbing outer layers.  This causes stray noise to reflect, much like a racquetball’s energy is quickly dissipated as it bounces from one wall to another and therefore drops to the floor.  

But it is not just its attenuation ability that brings accolades to this new product. The very fabrication process that gives MAJRabsorber™ those high levels of attenuation also allow it to be useful in a number of difficult applications.

Consider the possibilities with MAJRabsorber™…

  • Emi shielding materials special uses and applications.Because of the non-conductive outer layers, MAJRabsorber™ can be placed between close circuits without fear of shorting out sensitive components while helping isolate them..
  • The multi-layered approach also makes this material ultra-tough while remaining extremely flexible, which lends itself well to the production process for oddly shaped hardened enclosures, even remaining tear resistant for those difficult spaces during handling and transport.
  • With one of the many supply options being roll form, MAJRabsorber™ is not only cost competitive but it allows for quick turn-around times when cutting prototypes and even large production runs. This becomes a game changer for strict deadlines and tight budgets.
  • And for those enclosures which must stand up to challenging environments, engineers will be happy to note that MAJRabsorber™ is corrosion resistant and works well under both ends of the extreme temperature spectrum.

Tomorrow’s innovation for today’s EMI/RFI shielding needs:  That’s been MAJR Products’ mantra for 25 years. Look for MAJRabsorber™ in roll form (and quickly produced custom die-cuts), strips, sheets and pads in various shapes with no pressure sensitive adhesive (PSA) or PSA applied to one or both sides.  You’ll soon see it in the most progressive military or civilian electronic engineering programs, which are hopefully your own. MAJRabsorber™:  Only at MAJR Products.

Conductive Elastomers: Silicone vs. Fluorosilicone
Will Your Hardened Enclosure Remain Effective in Harsh Environments?

Conductive Silicones are often an essential component for hardened boxes and enclosures where environmental sealing and EMI/RFI shielding is required. The typical silicone-based gaskets and seals are impregnated with nickel, silver, copper, aluminum or other conductive particles to give non-conductive silicone their conductivity while providing IP rated environmental sealing that is required in many military electronic applications. These Conductive Silicone materials are also very flexible and can be formed into sheets, extrusions in various profiles, strips, washers and custom molded parts to fit almost any specific requirement, regardless of how unique.

But the one issue with these essential conductive silicone products is that they aren’t designed to withstand a harsh environment where they are regularly exposed to chemicals such as cleaning agents, oils or fuels.  Harsh chemicals cause the silicone to break down causing the environmental sealing protection and EMI shielding properties to be lost. These same Silicones can also lose their effectiveness due to galvanic corrosion between the conductive silicone product and the metal enclosure, especially in a shipboard environment. To defend your hardened box or enclosure that is exposed to chemical contamination or heavy salt fog MAJR Products recommends the use of conductive fluorosilicone materials.  This is a silicone elastomer which has been fluorinated to stop its breakdown when in contact with harsh chemicals but it maintains needed environmental sealing and EMI/RFI shielding characteristics.  “…fluorosilicone rubbers…have excellent resistance to aliphatic hydrocarbons and good resistance to aromatic hydrocarbons, oil and gasoline, animal and vegetable oils, dilute acids and alkalies, and alcohols; and fair resistance to concentrated alkalies.”¹

Like their conductive silicone cousins, conductive particles are added to the fluorosilicone base and the particles that should be used are dependent on your application.  The table below shows various options.

A comparative table of available fluorosilicone materials and uses from MAJR Products

When you consider the available number of sheets in various thicknesses or the number of extruded profiles and washers offered, MAJR Products can deliver chemical resistance, environmental sealing and EMI/RFI attenuation in a fluorosilicone component that meets your needs and exceeds your expectations.  

Fluorosilicone products in various forms from MAJR Products

Contact us by email or phone (at 877-625-6033) to discuss your unique military or commercial needs.  Our engineers will be happy to assist you in choosing the right fluorosilicone material and profile.

¹Encyclopedia of Corrosion Technology, Volume 20 of Corrosion Technology, Edition 2, revised, edited by Phillip A Schweitzer, P.E., CRC Press, 2004, ISBN 0824750446, 9780824750442, pg. 563.  

Custom EMI Ventilation Panels: An End to the “Square Peg – Round Hole” EMI Shielding Dilemma

Hardened enclosures come in all shapes and sizes.  When you compound the possibilities of various applications, industries, specifications and regulatory authorities, it’s no wonder that standard sizes, types or material for shielding a hardened enclosure rarely meet specific needs for any given project.  Even though most hardened enclosures are custom designed with specific requirements in mind they often have one thing in common: They all must breathe to allow cooling of sensitive electronic equipment while also being protecting from EMI/RFI.

Up until now this has been an ongoing problem for engineers.  Rarely are enclosures designed to be able to use standardized products for EMI shielding and air ventilation. Long and costly waits for a specialized EMI ventilation panel prototype are only the first problem.  Large production runs have been out of the question. It is almost as if the pre-existing EMI shielding vent panel dictated the size and configuration of the hardened enclosure. That’s like forcing a square peg into a round hole.

Need Round, Curved or Oddly Shaped Custom EMI Vent Panels?

MAJR Products, however, has mastered the trifecta of shape, size and speed-to-market for Custom EMI Ventilation Panels.  We are the leading EMI shielding products manufacturer that can supply specialized  vent panels engineered for difficult round, curved or specialized shape requirements and still maintain a high level of EMI/RFI attenuation and low upfront set-up costs.

Custom EMI shielded vents for hardened enclosures.

With a simple upload of specifications from a customer, MAJR Products can produce Custom EMI Ventilation Panels estimates often within a few days and provides in house technical assistance on design concerns before parts move into the production phase. In addition, MAJR’s Custom EMI Ventilation Panels can be produced in both Honeycomb Waveguide and Air Ventilation styles depending on the shielding and airflow requirements.

  • Custom Honeycomb Waveguide Panels are available in aluminum, brass, steel and stainless steel to meet the specific attenuation requirements of MIL-STD-461 and MIL-STD 810 by facilitating wavelength beyond cutoff.  While they can be made in a variety of shapes and sizes, they still allow for maximum air flow. With integrated gasketing material appropriate for the application, these custom waveguide panels can be supplied with captive fasteners or frame through-holes mounting options.
  • Custom Air Ventilation Panels also achieve attenuation of EMI/RFI noise while providing a minimal air pressure drop.  Most applications will call for an aluminum code-57 filter media and, when used with MAJR’s integrated gasket, will achieve EMI shielding to levels that meet or exceed commercial requirements.

Only from MAJR Products

We’re proud of the fact that MAJR Products is the manufacturer that can supply Custom EMI Ventilation Panels for round, curved or odd-shaped spaces more rapidly than anyone else in the industry.  We have developed internal mechanisms to incorporate custom designs into our high-capacity manufacturing and metalworking capabilities. The result:

  • No more “square peg-round hole” restrictions on honeycomb vent panel design.
  • Quick development and engineered to your specifications.

For those openings in hardened enclosures that are beyond the limits of stock, off-the-shelf EMI shielding vents, reach out today and – contact MAJR Products!  

MAJR Products EMI/RFI wire mesh grounding washers

EMI/RFI Wire Mesh Grounding and Conductive Elastomer Washers: Hardened Enclosure Shielding in Small Places

The smallest details are often the ones that will determine whether an EMI hardened enclosure will be compliant or will not  meet EMC requirements. That’s especially true when it comes to the many bolts, screws, rods or shafts that need EMI/RFI shielding or grounding.  When you have to attenuate a signal or ground components of an enclosure, don’t forget the EMI/RFI wire mesh grounding or conductive washer. Here’s what you need to know:

EMI/RFI Wire Mesh Grounding Washers

MAJR Products EMI/RFI wire mesh grounding washersEMI/RFI wire mesh grounding washers are made from wire mesh socks that look somewhat like thin knitted metal hoses before being compressed in a die to form the washer.  By altering the weight of the metal sock, various densities of washers can be made to increase or decrease the resilience. For example, a sock with a metal density of 15 to 20 percent will create a washer that can fill a gap or seam under pressure.  A starting density of 30 to 40 percent can create a washer which will snuggly fit a shaft or rod, which when compressed will act as a slip-ring to ground a rotating shaft to a metal enclosure. This gives the shaft needed EMC properties, eliminating unwanted EMI/RFI noise.

Besides needing to vary the thickness and density of EMI/RFI wire mesh washers, specific applications and environments often call for specific metals used in the mesh socks.  MAJR Products, for example, offers wire mesh grounding washers made of Monel, aluminum, silver plated brass, tin plated copper clad steel or beryllium copper. By varying the materials, density, thickness and inside/outside diameters, there are countless configurations and options available for any need or application within a hardened enclosure for both military and commercial uses.  This gives the engineer an impressive lineup of options. Popular applications include:

  • Signal and power connector panels
  • Door handle shafts
  • Hinge hardware
  • Grounding metal structures (i.e. equipment racks) to an electronic or electrical enclosure

EMI/RFI Conductive Elastomer Washers

Mounting application examples for MAJR Products conductive silicone washersConductive elastomer washers for EMI shielding and grounding are molded elastomer filled with conductive particles to provide the electrical conductivity and broadband shielding.  They are made of a variety of materials including silicone, fluorosilicone, or EPDM which stands up to fuel or chemical contamination. Their conductive particles can be aluminum, copper, nickel or silver, used singularly or in various compound combinations.  The various conductive materials used changes the performance characteristics of the washers and, along with varying the thicknesses, allows the washers to achieve a desired hardness and operating temperature range while accommodating differing MIL SPEC M83528/012X requirements.


Besides being able to attenuate EMI/RFI noise from inside and outside the hardened enclosure, elastomer washers are used:

  • To provide moisture sealing,
  • As a shock absorber,
  • To enable electrical grounding.

Like their wire mesh cousins, conductive elastomer washers can be made in almost any ID or OD size.

As stated earlier, the smallest details are often the most important when achieving attenuation and grounding in hardened enclosures.  With so many choices of materials, applications, where they are used and differing FCC, military and UL requirements, it’s important to use the right washer made of the right materials in the right size for any specific application.  There will be times when a conductive washer should be used over a wire mesh washer, or where silver is the preferred conductor over Monel or aluminum. But that’s the beauty of EMI/RFI grounding washers – they’re as adaptable as need be.

For help in determining what and how to use when, please contact the engineers at MAJR Products by calling 877-625-6033, or feel free to ask questions using the form on either of our web pages for EMI/RFI Wire Mesh Washers or Conductive Silicone Washers.