The CSF-1 helmet kit comprises a high quality bone conduction microphone and a speaker mounted on a leather covered bracket which attaches to a firefighting or rescue helmet. The microphone sits behind the user’s left ear and the speaker alongside the right ear.   It fits most models of helmet which have an adjustable ratchet type headband and connects to a portable radio using a INT-COM or PT series interface. It can also connect to hardwired communications systems.   Quick to fit and comfortable to use, the CSF-1 helmet kit provides excellent speech quality in high noise environments and when using SCBA.