Up to 500 meters intercom distance between 2 riders; Supports intercom between 3 riders; Up to 7 hours talk time; Receive a cell phone call automatically and safely; Advanced A2DP & EDR bluetooth function supports hands-free calls; Enjoy stereo music by connecting cell phone / MP3 / GPS through A2DP; Mount onto helmet with clip; Li-polymer battery: 500mA; Chip type: CSR; Waterproof grade: IPX4; Paring method: Long press both A and B intercom headsets power keys until red & blue LED flash alternately, short press one of the two headsets power key, then A and B start pairing automaticly; Once they sucessfully pair, blue LED flashes; If you want to pair A and C headsets, turn off A and B and setup A and C according to the above paring method; Pair B and C in the same way, then turn on A, B and C, you will find that A, B and C are all paired; Short press intercom call key to choose the person you want to talk to; They will pair automatically once turn on again.