M-105 Digital Transceiver surface unit (Surface to Diver)

http://www.cormetondivesupport.com/images/th-M-105-Digital-Transceiver-surface-unit-(Surface-to-Diver)1327490946.jpg
 The M105 Digital is a surface to diver communication unit which allows surface personnel to talk with divers in the water & vice versa. The unit uses a 6v DC lead battery, allowing up to 48hrs of operation, or may be hardwired to a 12v DC source. The system is activated only when the transducer is connected, preventing unwanted loss of battery power.

Includes:

Headphones & connection
Volume control & Loudspeaker
Water resistant case w/ pressure compensation valve
Battery charger
Connector & cable for external 12v DC source
Audio out cable