COMPATIBLE OEM# RBC18, BATTERY CARTRIDGE 18, SLA18 COMPATIBLE MODELS: APC BAY450, PS250, PS250I, PS450, PS450I, SC250RM1U, SC250RMI1U, SC450R1X542, SC450RM1U, SC450RMI1U, SU5005 SPECS: 12V (2 X 6V, 8AH) DIMENSIONS: 4.00' x 11.90' x 1.40' / 5.75LB TESTED, CHARGED AND READY TO INSTALL