Internal UPS circuits provide support for PCs during power failures, enabling a safe shutdown without data loss. Automatic Voltage Regulation (AVR) regulates brownouts back to usable levels without using battery power. Includes USB port to enable optional unattended system shutdown without data loss in the case of extended power failure. Built-in RJ11 phone suppression jacks protect modem, fax machine, cordless phone, or other peripheral with a standard dialup/DSL phone connection. Audible alarm and 4 front panel LEDs indicate UPS system and line power status. Cold start capability allows for temporary AC output during a power failure. Hot-swappable battery replacement makes changing batteries a snap.