DROK USB 2.0 Digital Multimeter, Volt Amp Capacitance Watt Meter, 7 Modes Multi Tester, DC 3A 12V Ammeter Voltmeter Power Meter, Charging System Tester, Fast Charging and Data Sync Dual USB Ports The USB monitor can display voltage, current, capacity and power, press the button to switch among seven different display modes Has two output: Output I is used for both charging and data transfer, Output II is for large current fast charging Multifunctions: capacitance checking, capacitance clear, over- and under-voltage alarm, over current alarm and Short-circuit alarm The display is clear and plenty bright enough, dual red color display; High accuracy and ultra-low resistance A great tool for testing phones, tablets, USB ports, power supply and charger outputs, and current demands of USB devices