This Nickel Metal Hydride battery from Battery Technology, Inc. is compatible with various models in Compaq's Armada and Contura notebook series as well as the Hitachi 350 series. It can be used as a replacement for the original battery if it has been damaged or misplaced, or as a second battery to keep charged for extended notebook usage when AC power is not available. The battery meets or exceeds the original equipment manufacturer's specifications. Don't let yourself be caught without power for your notebook when you need it. Get charged up with BTI's high-quality notebook battery products! Compatible notebooks include: Compaq Armada 1110, 1120, 1125, 1130, 1135; Compaq Contura 400, 410, 420, 430-C/CX; Compaq Contura Aero 4/25, 4/33C; Hitachi 350 series. Compatible Hitachi notebooks include: 350 series.