The updated Underwater Hearing Headset allows coaches to communicate directly with the swimmers while they are swimming! Coaches and swimmers love this technology in our effort to develop efficiency in swimming technique. Swimmers can hear the coaches and adjust their stroke while training. Instant feedback on stroke rates, times, stroke technique and feedback is invaluable. Coach wears the transmitter and the swimmers wear the headsets. There are 7 channels, so coaches can wear transmitters in one group and be talking to different swimmers. Up to 15 swimmers can wear the headsets and hear the coach on one channel. Swimmers can be up to 150 yards away from the transmitter. Transmitter can be plugged into an MP3 player so the swimmers can listen to music. Swimmers love the headsets as they are so comfortable to wear and they stay on at the fastest of speeds and while diving off the block. The bone conduction technology allows the swimmer to hear clearly. There is also a volume control. We find it’s so much easier for the swimmers to pay attention to coaches.