Used SUUNTO WIRELESS TANK PRESSURE TRANSMITTER LEDThe Suunto Wireless tank pressure transmitter gives you current tank pressure and remaining air time with just a glance at your wrist. Before your dive, simply pair the transmitter with your dive computer and youre good to go. The transmitters handy green LED light lets you know that its on. Suunto Wireless Tank Pressure Transmitter is compatible with Suunto D9, DX, D9tx, D4i, D4i Novo, D6i, D6i Novo, Vytec, Vytec DS, Vyper Novo, Vyper Air, and HelO2.