iFun4U USB Voltage/Amps Power Meter Tester Charging System Tester, Test Speed of Chargers, Cables, Capacity of Power Banks Multi-function: it is a power bank charging monitor with Capacity Current Voltage test function LCD Displays Current (Amps), Input Voltage: 3-7V, Input Current: &lt;3.5A, Capacity: 0-19999mAh Test using a USB charger, battery power bank or Micro USB Cable. Test your iPhone or Android phone Plug and Play: with USB input cable and microusb port, plug and play, without any extra devices needed Easy to read: it has been designed with backlight LCD, very convenient for you to read the data even in the dark