CoolMax HD-250BK-U2. Size: 63.5 mm (2.5 "), Hard drive interface: Serial ATA, Serial ATA II. Interface: USB 2.0. Compatible operating systems: Windows 98/SE/ME/2000/XP/Vista/7 (32bit/64bit), Mac OS 9.0 +. Colour of product: Black. Weight: 130 g, Width: 130 mm, Depth: 80 mm