Sienoc USB Voltage Current Meter Tester Charger Doctor tester Operating Range U/ 3 ~ 7.5V I/0 ~ 3A Resolution Voltage 10mV current 1mA The tester uses a new generation of power four semi-double loop integral converter IC, with a precision bandage reference, range accuracy, high precision, stable and reliable performance, strong anti-interference ability, high temperature can be used for measuring USB powered or power consumption of the interface, mobile phone charger, U disk and other products.