Features: Simpleandconvenienttouse. Portableandeasytocarry. Thevoltageandcurrentwillbedisplayedcircularly. plugandplayitcanworkwithoutadditionalpowersupply. TheUSBtestercantestvoltageandcurrentofthepowersupplyequipmentwithUSBport. Specifications: Type:tester Voltage:3.5V-7V Current:0-3A Color:Blue Size:5.1x2x1.5cm PackageContents: 1xUSBCurrentAndVoltageTester