Macally 3.5" FirewireB (800) and USB2.0 combo HDD external storage enclosure, Aluminum. Size: 88.9 mm (3.5 "), Hard drive interface: Ultra-ATA/133. Interface: USB 1.1, 2.0, IEEE 1394, IEEE 1394b. Compatible operating systems: Mac OS 9.2, Mac OS X v10.1.5, Mac OS X v10.2.4 Windows 98SE / 2000 / ME/ XP, Minimum system requirements: FireWire, USB. Weight: 0.59 kg. Power requirements: 100-240 VAC