Ever wondered, "Have I got enough water to stay another one or two days free camping?" We have the solution ? NO MORE GUESS WORK. Topargee RV, Caravan & Marine Accessories have three exclusive water tank gauge models that will count down your water usage by the litre/gallon. They are designed to suit your specific needs and take out all the guess work of knowing how much water you have left in your tank. H2F-BT12 Bluetooth - use on your smart phone or tablet as the display. H2F-FM Flush Mount - designed to provide a superior appearance as the display is in to you vehicle H2F-SM Surface Mount - suited more to the DIY aftermarket. This is a MUST have for those loving the adventures of bush, free camping & boondocking as you will always know your daily water usage and you can plan your adventure more accurately.