Remote battery watering systems let you fill all batteries to proper electrolyte levels from a single fill tube, using a simple hand pump. Pro-Fill On-Board Battery Watering System, 6-volt RV Edition, provides the most convenient and accurate means of filling and maintaining proper battery water levels. Hard to reach batteries are just as easy to fill as batteries on a workbench. Several batteries can be filled safely and simultaneously from a single remote position without ever having to touch a battery or remove a cap. Pro-Fills automatic control valves ensure each cell is closed when the precise level is reached. Safer and more accurate than conventional filling. Improves battery life and performance. Hard to reach batteries are as simple to fill as batteries on a workbench. Several batteries can be connected and filled at the same time. Automatic shut-off prevents over or under watering. Simple hand pump operation. Use with any distilled water container. Quick disconnect feature allows supply to be attached in a snap. No need to remove vent covers Requires Handy Pump (SKU 27036) to operate Eliminates need to remove vent covers to fill Automatically sends water to low cells only Installs in minutes, no tools required | Flow-Rite Controls Pro-Fill RV Edition Dual 6-Volt Battery Watering System