Sealed Lead Acid battery with 2 contacts on top. 6 Volt SLA UPS Battery. Fits models; APC 200DL, APC AP200, APC BackUPS 1250B, APC BackUPS 250, APC BackUPS Office 400, APC SmartUPS 250, APC SmartUPS 400, Easy Options 250VA, Leadman LU-650A, SL Waber PowerHouse 420T, SL Waber Upstart, Tripp Lite BC250, Tripp Lite BC400 LAN, Tripp Lite Master