ELEGIANT 5A/9V Dual-usb Charger Doctor Voltage Current Detector Digital Ammeter Voltmeter Multimeter USB Tester Mobile Power Panel Monitor for Smart Phone Charger Power Bank (Grey) You can use it for almost everything about electronics with USB charging. This product can measure voltage USB power supply equipment, empty load, the voltage and current. Allow you to test double devices at the same time. Accurately show Voltage of 3-9V, Current of 0-5A. Perfect to detect your phone charger or power bank to avoid overloading.