The Q-R1U model has an innovative form that allows the unit to be used as either a free-standing unit, or to be rack mounted with a minimal footprint (1U). The unit also features 2 built in serial ports to allow for control of two computers during a power failure. Built-in Automatic Voltage Regulation (AVR) insures that your connected equipment receives only regulated, consistent power. The battery-pack has four (4) 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.