Special Features:

Diver recall system/push to talk underwater public address; used in underwater movie production; recalling scuba divers, interrogating suspicious divers; 180db output, 25ft cable/phone plug installed on commercial/military ships; 100 watt amp, rear connections

Properties:

A manually operated device which converts mechanical power into electrical energy for actuating an audible tone and may also actuate a visible signal at a similar remote station. It also receives electrical energy from another similar station and converts it into acoustical energy and may also actuate a visual signal. Includes a hand ringing generator, audible signalling device and cabinet. May include a selector switch, visual signal or volume control. See also generator, ringing, hand.