DROK Pocket Digital Multimeter USB 3.0 Hub, OLED Display DC 13V Voltage Ampere Power Capacity 4in1 Multi Tester

3 MODE USB MONITOR: Our sophisticated versatile USB digital multimeter kit is a utility tool for measuring voltage, current, capacity and power via your phone/battery. One button achieve the switching of 3 different modes (direct mode, quick charging mode and disconnected mode), super simple to evaluate whether the USB charger are outputting acceptable voltage/current to your device.
HIGH QUALITY OLED DISPLAY: 0.91