Stop lugging your AC adapter back and forth between home and office. Get a second AC adapter for your notebook and keep one in the office and one for home or travel. The 240-Watt AC Adapter from Dell is specially designed to meet the power needs of your Dell laptop. Packed with of 240-Watt power, this adapter enables you to simultaneously operate your system and charge its battery from electrical power outlets. This product is compatible with the following systems: Precision 7520; Precision 7720; Alienware 15 R4; Alienware 17 R5; Alienware M17; Alienware Area-51M; Alienware M15 R2; Alienware M17 R2.