Features: The USB power tester can measure USB charging voltage, current, and discharge capacity over time. The USB power tester is designed with a reset button, and you can press it for 3-5 seconds to clear the screen. Can easily measure the operating current of the output voltage of the USB port and equipment. Small size, no power and other auxiliary equipment, plug and play, and can also detect whether the USB charger's output voltage and current are standard, suitable for factories, laboratories, and users. Can be used to check the performance of USB cables, wall chargers, car chargers, and power banks. 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: About 0.1 Note: Please allow 1-3cm error due to manual measurement. Make sure you don't mind before bidding. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1X USB Tester