Tactical Radio Connector Cable & Push To Talk Adapter for Headset: US/Civilian Wiring, Select ComTac III Models and Select Helicopter Headsets - EF Johnson: All 51, 5000, 5100, 7700, 8100 Series, Ascend, Kenwood VP400, VP600, VP900 & MoreP N: NXC 23RR: For EF Johnson: 5000, 5100, 8100, 51SL ES, 51 Fire ES, 51SL ES, 51LT ES, 7700, Ascend, AN PRC127EFJ, Kenwood VP400, VP600, VP900 & More. Helicopter Helmet Comms Compatible! Push To Talk on the Radio Adapter. Compatible w : US Civilian Wiring, Select ComTac III Models and Select Helicopter Headsets. Utilizes the standardized NEXUS TP 120 Connector. Features a removable adapter, cost saver when switching radios agencies. Push To Talk(PTT)