Tripp Lites U357-025-R is an inexpensive way to create an external USB storage drive, ideal for laptop / notebook users. Simply insert any manufacturers SATA 2.5" hard drive ( not supplied ) into the rugged ABS case, and plug the included USB 3.0 cable into a computer or hub USB port. Unit is Plug-n-Play...no software to load. At only 5.25"L x 3.25"W x .5"H, the U357-025-R travels easily...great for storing large files like photos, music, movies, etc. Compatible with Windows 2000, XP, Vista, Win7, and Mac OS 9.2 and above. Supports USB 3.0 data transfer rates up to 5Gbps, provide USB source is USB 3.0.