This 3000 watt inverter charger produces a pure sine wave, which some appliances require for use. So it can run laser jet printers, computers, televisions, CPAP machines and other medical equipment. In the event of a power outage, this inverter combined with a battery bank can be used to power a few lights, a refrigerator and perhaps a few other necessities. Also great for emergency backup power applications is the automatic transfer switch on this unit, which keeps the power supply uninterrupted in the event of an outage. With the inverter hooked up to shore power, it will detect the loss of electricity and start pulling energy from a connected battery bank instead to keep the power supply constant.