WD  120 GB External USB 2.0 Hard Drive with Dual Option Backup Dual-option Backup -- choose how and when to back up your data, automatically or on-the-spot USB 2.0 interface -- high-speed connection for maximum throughput Front-mounted power button -- equipped with WD's exclusive Safe Shutdown feature that ensures all data has been safely transferred before shutting down the drive 7200 RPM rotational speed Preformatted -- simply plug it in and go