Sealed Lead Acid battery with 2 contacts on top. 12 Volt SLA UPS Battery. Fits models; APC BackUPS 650 Pro, APC BackUPS 650M, APC BackUPS 650MC, APC BackUPS 650SC, APC BackUPS 650X06, APC BackUPS Pro 650, APC BackUPS Pro 650PNP, APC BackUPS Pro 650S, APC SmartUPS 620NET, APC SmartUPS 650, APC SmartUPS VS650, Data Shield AT5000, Deltec PRM700