The Sena 10S Motorcycle Bluetooth Communication System is an upgraded version of the original SMH10 system, which has proven itself roadworthy to motorcyclists everywhere. Now in a slimmer profile, the 10S maximizes the enjoyment factor of your ride by keeping you in touch with up to four riding companions via crystal-clear HD audio, up to 1.6 km (1 mile) away, through the One Touch Group Intercom. The 10S also uses the Universal Intercom protocol so it can communicate with all Sena and non-Sena Bluetooth headsets on the market. Operating temperature: -10˚C - 55˚C (14°F - 131°F),Speaker: driver unit 40 mm – thickness 6.5 mm,Boom microphone length: 183 mm, Radio frequency specifications: 76 - 108MHz,Radio region: worldwide,Built-in FM radio with RDS AF (Radio Data System Alternate Frequencies),10 preset station memory with automatic scan function, BATTERY: Charging time: 3 hours,Type: Lithium polymer