Qualified to BS9520 G0001, BS9522 F0029 and meets the requirements of MIL-C-D38999 series 1.  They are bayonet locking and 100% scoop-proof.  The free plug has a grounding ring as standard which gives a typical RFI screening performance of 90dBs at 100MHz and 85dBs at 1000Mz.  Connectors are environmentally sealed without the need for a rear accessory.