This 5000 Watt pure sine inverter with GFCI uses a D.S.P. (Digital Signal Processor) driver to safely generate a pure sine wave at a high quality 120 VAC output. The product responds to the high and low battery voltage changes and adapts to its output perfectly to ensure a stable 120 VAC. The innovative technology of this pure sine inverter will support the usage of sensitive loads. All DC and AC operations are automatically controlled by the D.S.P. program. The improved efficiency of this inverter ensures nominal output voltage even at low input DC voltage. Since the output voltage is 3% of the variation input voltage stable power will always be produced for your AC loads. This inverter has excellent driving power with a surge output that’s 2 times higher than the output capacity. This allows you to exceed the output for a short period of time (500 milliseconds) to power some devices with a quick startup surge. With various protection circuits built in, this product will automatically shut down at low voltage or in the event of a sudden change of input/output power. The inverter also shows excellent performance and reliability control during rapid environmental changes such as ambient temperature.