SimpleTech S640U 640GB SimpleDrive Turbo USB 2.0 External Hard Drive (Black) SimpleTech SimpleDrive Turbo 640 GB USB 2.0 3.5-inch External Hard Drive General Features: Color: Gray 640 GB capacity 3.5-inch hard drive Slim design takes up little space Turbo USB 2.0 interface, up to 25% faster than USB 2.0 (compatible with USB 1.1) Sits flat or stands upright with included cradle Built-in cooling vents Automatically powers on or off with your computer