6000 watt pure sine inverter The inverter transforms DC (direct current) power stored by batteries into AC (alternating current) electricity that can be used to power tools and appliances of all varieties. A built-in 50 amp transfer switch allows the product to automatically switch from using a battery bank to shore power. This is great in the event of a power outage, as the product will automatically detect the outage and redirect power from your backup battery bank. It also has a built-in 45 amp battery charger which uses AC power, from the grid or from a fuel-powered generator for example, that can be used to recharge a battery bank as well. The battery-type selector on the top of the unit allows the ability to adjust the voltage provided to the bank. url:http://www.rogerele.com