Bring all of the sound of your onboard audio system right into your helmet with the Sena 20S Helmet Clamp Kit. The adapter cable with 7-pin DIN plug connects the onboard audio system to the helmet clamp and allows users to listen to the onboard audio system| including FM radio and GPS navigation. The CB radio retains full functionality via use of the integrated PTT switch/button and clamp kit microphone. When paired up with a Sena 20S main module| all sounds - CB radio| GPS navigation| and FM radio - from the onboard audio system can be mixed with Sena 20S sound sources| including intercom| MP3 music| and phone.