The CA2 bus-powered portable hard drive delivers superb performance and reliability for both Mac and PC users. The drive is equipped with the industry's best Oxford chipset, which is approved by many hardware and software manufacturers. The drive includes a patented internal mechanism and anti-shock strip to maintain drive stability and help prevent damage due to impact, drops, and excessive movement. Finally, the HDD spin-down feature ensures efficient operation by reducing power consumption. When your computer enters sleep mode, the hard drive spins down to minimize power consumption. The hard drive spins up automatically when the host system wakes up.