The MF72 power NTC thermistor is a kind of semiconductor ceramic element that mostly made from transition metal oxide material, and belongs to negative temperature thermistors. When you tune on an electrical equipment , the surge current can be restrained by a power NTC thermistor connected in series with the power circuit .Because of the continuing action of current, temperature of power NTC thermistor raising, the resistance will rapidly drop to a small value, the consumed power can be ignored. So it can not affect normal operating current. Therefore, using power NTC thermistor is a most effectively amd most brief measure to restrain surge current, protecting electrical equipment from destruction.