Features: Simple and convenient to use. Portable and easy to carry. The voltage and current will be displayed circularly. plug and playit can work without additional power supply. The USB tester can test voltage and current of the power supply equipment with USB port . Specifications: Type: tester Voltage: 3.5V-7V Current :0-3A Color: Blue Size:5.1 x 2 x 1.5 cm Package Contents: 1x USB Current And Voltage Tester