Absorbent Glass Mat (AGM) technology for superior performance.Valve regulated, spill proof construction allows safe operation in any position.Power/volume ratio yielding unrivaled energy density.Rugged plastic case and cover.Approved for transport by air. D.O.T., I.A.T.A. and F.A.A certified.UL recognized under file number MH20120.Possible Replacement for: PS-640F, PC4.5-6F1, PC4.5-6XBF1