The Verbatim 53021 500GB external hard drive offers extra data storage to free up the space on a computer's hard drive 2.5" Portable - These are more compact and lightweight than the desktop versions, making them ideal for computing on the move and are perfect for use with laptops Automatic synchronise system (Nero BackITup2 Software in 26 languages for Windows XP and Vista) to back up files - no need to worry about making a back-up New unique and stylish design Ideal for travelling as only weighs 150g Compatible with Windows 2000/XP/Vista, Mac OS 9x and Mac OSx10.1 or higher Capacity: 500GB Holds approx. 160,000 photos (1.MB photo size), 125,000 MP3s (4MB MP3 file) or 500 video files (650MB video file) Dimensions: 135mm x 85mm x 25mm Weight: 168g