Automaticly to change unit of the capacity, when it is lower than1A, unit-display when it is higherthan1A, unit-dispaly is changed to A. PWM 1us , the width is changable by adjusting button. The watt meter is also supporting to display working hours. WM150 is a Watt Meter, which is capable to test power, current data of the electric equipment, like servos, 1-50V power, current is up to 150A, the precise accurate to 10mA.USB firmware updates, easy to operate.