The Mares Quad Air Dive Computer's LED Tank Module is mounted onto an HP port of the first stage regulator, and its main function is to transmit tank pressure data via hose-less coded RF protocol to the dive computer (for computer see SKU: MRSQA). The dive computer then displays the tank pressure and calculates gas consumption rate and time remaining before reaching the reserve value. For this to happen, the tank module and the dive computer must be paired. The LED tank module features also, as the name suggests, an LED on the top of the tank module body. The LED can be used on the surface before a dive to distinguish between a full and an empty tank without needing a dive computer to display the exact value. During a dive the LED blinks when certain pressure levels have been reached and can thus alert your dive buddy or dive guide when you have reached the half tank mark or the tank reserve.
The tank module turns on automatically upon pressurization to at least 145 psi (10 bar). It turns off automatically when the pressure drops below 145 psi (10 bar). To save battery power, the tank module turns itself off also when the pressure does not change over more than 4 minutes. This prevents unnecessary battery consumption in case of a pressure check well ahead of a dive with the tank left open afterwards, or in case the tank is not closed, and the first stage purged immediately after a dive, or in the case of stage tanks that are left pressurized during the dive even when not in use. The tank module turns itself on again when a difference of pressure of more than 14.5 psi (1 bar) is sensed.