Sporty's headset adapter as pictured. Great for experimentals, ultralights and other aircraft without a power system. This adapter enables you to use general aviation dual plug headsets with Sporty's handheld radios. General info from manufacturer:
Plug your standard twin plug general aviation headset into this adapter, and you can use your radio without taking off your headset. Makes use of your headset speakers and microphone. With Sporty’s SP-400, there is even side tone – so you can hear yourself talk when you make transmissions. Works with Sporty's JD-200, SP-200 and SP-400.