This battery back up has 2 great uses. First you can connect your computer or central electronics to it for electrical protection along with battery back up in case of power loss. This unit will supply power to an average computer for about 10 minutes. If you connect the enclosed USB cable to your "Windows" computer and load the enclosed software, your computer will shut down safely once power levels get to low. Another great use for this unit is to connect your unmodified VHS or DVD players to it. If you have a quick power outage, this back up will keep your players running for a few minutes. This eliminates the need to turn on, play and set auto repeat on all your players manually. This unit has 3 surge protected outlets and 4 battery backed up outlets. 500 Volt Amps.