Amstron replacement APC S20BLK batteries. These 12V 7Ah batteries are designed to replace your existing Replacement Battery Cartridge, you will need to use your existing wiring or trays to make a complete unit.Requires existing wiring or tray from old unit 4 batteries ship FeaturesAbsorbent 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. Approved for transport by air. D.O.T., I.A.T.A., I.C.A.O., F.A.A.