... against output short-circuit; against overload, high voltage and low voltage protection , over heating protection,battery anti-polarity protection, ... 50hz±1%50hz±1%DC voltage12V24V48v48VO/P waveformpure sine wavepure sine wavepure sine wavePure sine waveTHD≤3%≤3%≤3%≤3%Transfer time≤4ms ... -circuit,over load,high-voltage,reverse polarity protection and low-voltage protection pure sine wave inverter 110V