This is a high performance, compact, and easy to use unit. It is made to respond to the demands of communicating with divers in action without carrying expensive, complicated and heavy units. The size of the main unit is similar to a cellphone. The main unit has a PTT (Push to Talk) button and a headphone/microphone connector. The unit turns on when the headphone/microphone is connected to the main unit. The unit turns off automatically when the headphone/microphone is removed. A 10 meter (33 feet) transducer cable connects to the main unit and is lowered into the water. Sku 33054 - OR002565 - OR023006