... call answer, call reject, call hang up bluetooth intercom helmet(1) Wireless headset for bluetooth enable cell phone at ... Up to 5 hours talk time when using the intercom feature. Up to 300 hours standby(2) Call ... play, pause(9) Automatic switching among bluetooth cell phone, intercom, stereo music, FM radio.(10) With DSP echo cancellation ... proof, while the design is durable. bluetooth intercom helmet