Totally up to date modern electronics have been carefully selected and tested to give the clarity you would expect from modern surface communications equipment - even with standard microphones and earphones found on most dive sites.

Separate diver inputs on two-pin 4mm terminal posts.
Headset is also available as an option.
Speaker or headset for tender operator. (Optional)
Hand-held PTT microphone as standard.
Mains trickle charge to heavy duty battery.
Recording output.
Waterproof speaker with high quality sound.
Transformer and Opto-isolation of diver side wiring for safety.
Output for recording device or external speaker.

12v external battery input for back-up.
External speaker output.
Diver selection switch.