DROK® Mini OLED USB Current Voltage Tester Meter Charger Detector Multimeter Power Capacity 0-99999mAh; 0-30.00W; DC 0.00-3.00A; DC 3.50-13.0V Ampmeter Voltmeter Multi-in-1; Mobile Testing Power Monitor with Screen Rotation Function; Power-off Storage Function; Over- and Under-voltage Alarm Function Review