The HM 100b open face helmet headset and PTT system is an accessory for use with new Cobra pmr446 2 way radios. Making use of a 2 way radio is a convenient and safe way to communicate while riding a motorcycle snowmobile ATV or any other activity in which an open face helmet is worn. The HM 100b features a open face helmet headset boom microphone with 2 ultra thin speakers and flexible boom microphone that attach quickly and easily inside the helmet. A weatherproof handlebar mount push to talk (PTT) switch puts control of the 2 way radio at your fingertips. Generous cable lengths and helpful accessories make installation easy and professional looking Key Features Ultra thin speakers for use inside helmet Flexible boom microphone Weatherproof handlebar mounted Push To Talk button