Features: USB power tester can measure USB charging voltage, current and discharge capacity over time. USB power tester has designed with reset button, and you can press 3-5 seconds to make the screen cleared. Can easily measure the operating current of the output voltage of the USB port and equipment. Small size , no power , and other ancillary equipment, plug and play also detect USB charger output voltage and current are standard suitable for factories, Laboratory and users. Can be used to check the performance of USB cables, wall chargers, car chargers and power banks. Package Includes: 1X USB Tester Specifications: Material: ABS Size: 74x23x13.5mm/2.91x0.9x0.53in Voltage: Input / Output Voltage: 3-9V, Voltage Resolution: 0.01V Current: Input / Output Current: 0-3A, Current Resolution: 0.01A Accuracy: 1% Line Loss: Aabout 0.1 note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item.