DESC: WD quality inside and out - Designed with the same commitment to quality that made WD external drives the number one selling drives in the world. Plug-and-play simplicity - Just connect the power and plug it into a USB port to instantly add more storage to your computer. Designed to save power - Turns on and off with your computer. Enters idle mode when not in use. Utilizes a WD drive with power-saving WD GreenPower Technology™ and an EnergyStar compliant power supply. Earth-friendly packaging - Packaged in a minimized eco-friendly, recyclable packaging made from recycled materials. Preformatted for PCs - Designed for use with Windows-based computers. Can be easily reformatted for use with Macs.