Acomdata HD500UHE5-72 E5 HybridDrive 500 GB USB 2.0 External Hard Drive USB 2.0 external hard drive with 500 GB capacity for Mac and PC 16-bit RISC processor for up to 22% faster data transfers; 7,200 RPM spin speed for fast read/write Engineered to dissipate heat efficiently without fan; stacks horizontally or vertically Includes stand, USB cable, AC adaptor and power cord, CD-ROM with USB driver, user's guide, and mail-in product registration card 1-year limited warranty