The 1500AVR model has an innovative form that allows the unit to be used as either a free-standing unit, or to be rack-mounted. The unit features 2 built in serial ports to allow for control of two computers during a power failure. This model features Automatic Voltage Regulation to insure that your connected equipment receives only regulated, consistent power. The battery-pack has four 7AH batteries for extended runtime and is hot-swappable to minimize downtime. This model is ideal for corporate servers, departmental servers, UNIX servers, as well as mission-critical network components.??CyberPower's OfficePower 1500 Battery Back-up System not only guards against surges and spikes, but will also step up low voltages or step down high voltage conditions to safe output levels without resorting to battery power. The OfficePower 1500AVR also protects your computer system and valuable data during a power outage. In the event of a power outage, the included PowerPanelPlus Software autom... Minimize