Powered by MULTIVOICE technology, OTTO Connect 200 Series supports up to 8 simultaneous speakers on single channel and virtually unlimited listeners over secure and clear communications network. Intercoms and headsets feature full-duplex, hands-free communication over distances up to 4,000 ft and with up to 18 hours of talk time. Operating in 900 MHz frequency band, each intercom has 6 channels and comes with user's choice of headset equipped with DSP noise-canceling technology.