Advanced DSP and 3-leveltechnology,output power factor correction (APFC), input power factor upsto0.99, High efficiency 95% (up to 98% in ECO mode ), Advanced digital paralleltechnology, 3:1 to 1:1 model settable, wide input voltage range (190 - 499vac)and frequency range (40 - 70 hz),50/60 hz frequency auto sensing,two modes offrequency conversion :50hz input / 60hz outout or 60 hz input / 50hz output