We offer the genuine battery model PSG-480. This 4 volt battery has an amp hour rating of 8ah. This state-of-the-art lead-acid battery is sealed and maintenance-free, which fixes the acid electrolyte in a gel or in an absorptive fiberglass mat for maximum performance. The advantage of this design is that the battery needs no water additions, can be operated in any position, and can be used in close proximity to people and sensitive equipment. Trust Battery International for all of your battery needs.