See detail @ http://www.amazon.com/gp/product/B00429N19W?&tag=externalharddrives0a-20 The CyberPower CP1500PFCLCD PFC Sinewave UPS System with pure sine wave output and multifunction LCD safeguards mid- to high-end computer systems, servers and networking hardware that use conventional and Active Power Factor Correction (PFC) power supplies. Its automatic voltage regulation (AVR) topology delivers clean and consistent AC power, protecting connected equipment and preventing costly business interruptions. Its patented GreenPower UPS advanced circuitry reduces UPS energy costs by up to 75% compared to competitive models.