This On-Board Battery Filling System fits six volt 4 Battery Systems. A pump is included (pumps can be shared between systems)

It provides the most convenient and accurate means of filling and maintaining proper electrolyte levels. Hard to reach batteries are just as easy to fill as those up front.

Batteries can be filled safely and simultaneously without ever having to remove a cap. Simple hand pump with quick disconnect uses any distilled water container. 

 Fits all standard 6 Volt Batteries such as Crown, Deka, US Battery and Trojan