Check the listing for details. Ocean Reef Surface CommunicationDual Unit Scuba Diving M-105. Condition: New. Listed at 1429.95 USD. Ocean Reef Surface Communication Dual M105 DIGITAL Surface to diver unit (transceiver unit), allows communication with any number of divers wearing wireless comm units. Direct communication with PTT walkie-talkie, it uses 6V DC lead battery and allows up to 48 hours of operation. Can be powered with a 12V DC source. Activated only when the antenna is connected to the unit to prevent unwanted loss of power. It comes with 10mt (approx. 33ft.) transducer cable length. Available in different lengths on request. Long cables may require amplifier mounting. This product also includes: Headphone connection. Volume control. Speaker. Water resistant case pressure compensation valve. Battery charger. Easy to read LED battery tester which shows the power status of the battery. Transducer cable. Microphone.