Hittime New USB Power Portable Mini Current Voltage Tester Detector Blue Brand new and high quality. It can measure current and voltage of the power supply equpment with USB port. Plug and play, no extra power supply needed. The voltage and current will be displayed circularly. small sized, easy and convenient to carry. Workable range: U=3.5 - 7.0V, A=0 - 3A. Resolution: voltage 10mV, current 1mA. Error range: voltage &lt;1%, current &lt;2%. Full-scale voltage drop:200mV. Workable temperature: 0 - 60. Size: 5.2cm x 1.5cm x 3.4cm.