Etree Noise-Cancelling Motorcycle Helmet Bluetooth Headset and Intercom with Handsfree Calling for Shoei , Arai , Scorpion , Icon and More Black Special for clear communication on motorcycle riding; Interphone function-talk to another interphone in 150m distance; Multipoint-connect 2 Bluetooth devices at the same time; Waterproof-no compromise in water; Speaker booster-clear sound and easy communication; GPS support-hear GPS direction information from Moto-friendly GPS; Easy to installation and dismantlement; Safe auto-receiving cell phone calls; All weather, waterproof design; Reduce wind and road noise to get clear communication; Motorcycle or vehicle speed up to 90km/h for intercom and 70km/h for phone call; Pairs up to 8 Bluetooth devices.