Circular Backshells

Amphenol Ltd offer a wide range of environmental and EMI backshells for circular connectors including strain relief clamps and adaptors for heatshrink boots and overmoulding.

Request a quote or more information on our range of circular connector backshells using our Enquiry Form

Backshells provide strain relief, environmental sealing and EMI/RFI shielding.

Availble as RoHS compliant, our selection of termination accessories are available in Aluminium, Stainless Steel, Aluminium Bronze, and come in various finishes. Different exit angles (i.e. straight, 45, and 90 degree) are available and customisation is always an option.

Some Backshells can be used without any additional protection while other types are generally used with heat-shrink boots or similar protection/strain relief mechanism depending on specific requirements.  Our most popular backshell style is the BK4 Band Lock Adaptor for screened cables which can be supplied with or without termination band and heatshrink boot.

Backshells for Military & Aerospace applications are governed by SAE, AS85049 standard and Amphenol Backshells are designed to meet the applicable requirement of these standards. Amphenol offers additional styles and designs and can support you from concept to product realisation to satisfy your unique requirements and specifications.

Applications for circular backshells include: Wire Bundle and Cable Management, Lighting, IFE and Galley, Avionic Control, Instrumentation, Aircraft Power Distribution, Weapon Systems, Actuation and Sensors, Radio/Datalink/Antenna/C4I, Shelter Power Management; Military, Commercial Aerospace, Industrial

Amphenol backshells are supported by our distribution partners, PEI Genesis stock M85049 mil-spec backshells, and BK4 Band-Lock Adaptor series backshells are available from RS, Farnell and Acal BFi. Acal BFi has the most extensive range of BK4 products stocked in various plating finishes and entry sizes.

You may wish to visit to build or cross-refer a part number. Or see our guide on how to select a backshell.

For Mil-DTL-38999 Series III  use connector group "L"



Band Lock Adaptor (BK4)

BK4 Band lock adaptor backshell braid trap military - Most popular for screened cable termination
- Use with heatshrink boot or moulding
- Screen termination with retention band 
- Alternative to Polamco 91H1 / BTA1 series
- Click here to download the drawing datasheet



 Backshell (BN1)

non environmental backshell - M85049/21, M85049-29
- Good strain relief
- No environmental or EMI protection
- Alternative to Polamco 77H series
- Click here to download the Catalogue


Environmental Backshell (BE1) environmental backshell adaptor - M85049/7, M85049/9, M85049/11
- Good strain relief and sealing 
- Suitable for 6 foot water immersion
- Suitable for harsh environment applications
- Click here to download the Catalogue


Non-Environmental EMI/RFI

 Backshell (BM1)

Non Environmental RFI EMI Backshell screen termination accessory - M85049/19, 23, 24, 25, 36
- Good strain relief
- 360-degree screen termination
- Accomodates individual & overall shielding
- Click here to download the Catalogue


Environmental EMI/RFI

 Backshell (BV1)

Environmental RFI EMI Backshell sealed screen termination accessory - M85049/6,8,10,17,78
- Good strain relief and sealing
- Offers excellent shielding and sealing.
- Accomodates individual & overall shielding
- Click here to download the Catalogue


Shrink Boot Adaptor (BB1) Shrink Boot Adaptor Accessory - M85049/60-1, M85049/62, M85049/69
- For unshielded cables
- Terminated with heatshrink boot
- Groove for heatshrink boot lip
- Click here to download the Catalogue


Crimp Ring Adaptor (BC1) Crimp Ring Adaptor Screen termination accessory backshell - M85049/20 and M85049/26-3
- For screened cables 
- Terminated with heatshrink boot
- Crimp ring supplied to fix cable screen
- Click here to download the Catalogue


Band Lock Adaptor (BL1) Band Lock Adaptor BL1 accessory backshell - M85049/82, 83, 84, 85, 86, 87, 88, 89, 90
- For screened cables
- Terminated with heatshrink boot or mould
- Tempered band / band-it to fix cable screen
- Click here to download the Catalogue


Pre-Shielded Adaptor (BH1) Pre-shield Adaptor BH1 Polamco series 70H pre-braid backshell - M85049/109,111,112,114,115,117
- For screened cables 
- Supplied with a length of braid attached
- Alternative to Polamco 70H series
- Click here to download the Catalogue


SQ Adaptor (BU1) SQ adaptor backshell BU1 - For screened cables
- Cost effective braid termination
- End nut tightened over cable shield
- Used with heatshrink boot
- Click here to download the Catalogue


Quick Clamp (BQ1) Quick Clamp BQ1 - M85049/15,16, 53, 54, 55, 56, 57, 63
- Used to tidy-up cables
- For weight critical applications
- E.g civil and military aircraft
- Click here to download the Catalogue


Strain Relief Clamp (BS1) Strain Relief Clamp - M85049/38, 39, 43, 47, 49-2, 51, 52
- Provides strain relief & cable tidy
- No environmental protection offered
- Alternative to Polamco 96H / 97H1 series
- Click here to download the Catalogue


Grommet Nut (BG1) Grommet Nut - M85049/14, M85049/27, M85049/31
- Holds grommet and contacts in place
- Used when no backshell required
- Eliminates cost of backshell
- Click here to download the Catalogue


Lamp Thread Adaptor (BP1) Lamp thread adaptor backshell - Threads similar to lamp base
- Nut or clamp termination
- Strain relief with or without heatshink boot
- Alternative to Polamco 95H series
- Click here to download the Catalogue





Contact List for Partners and Distributors

Amphenol corporate

Worldwide Vision Connecting People with Technology

Rhino 38999

High Power up to 1000A