The Liebert PSA is an Economical, Line-interactive, uninterruptible power supply (UPS) that offers full-featured power protection for small office computers and electronic equimpent. Liebert PSA offers unique features and extraordinary preformance not normally found in similair products in this price range. Liebert PSA provides up to five minutes of back-up time at full load -- more than enough to save work in progress and shutdown the connected equipment. USB shutdown software and a USB cable are also included. The UPS offers three or six battery-backed outlets, and one or two surge-only outlets.