J-DEAL&reg; USB Mini Charger Doctor, Amp Volt Digital Reader, Current Voltage Detection Tool, Mobile Power Charging Monitor, Backlight Display, White(3V-7V) Tester three dimensional size 60 * 28.5 * 15mm (without cable), about 14 cm length of the line This test can be a USB charging current, voltage, discharge capacity, intelligent devices. It can be very easy to find digital device charging problem.