bluetooth helmet 1 support 500 meters duplex intercom 2 answer, reject, dail, hang up cell phone bluetooth helmet(1) Wireless headset for bluetooth enable ... for rider& passenger or two separate bikes up to 500 meters.Up to 10 hours talk time when connected to ... AVRCP: forward, backward, play, pause(9) Automatic switching among bluetooth cell phone, intercom, stereo music, FM radio.(10) With DSP ...