Multi-functional USB meter. USB meter tester is mainly used to detect USB charging current, voltage, capacity, power, time, etc, displaying accurate data in real time; detecting the quality of charger and cables, providing a safe charging environment for your valuable devices. USB tester can automatically detect different fast charging protocols. Power-off Memory Function: Testing the capacity of a power bank requires completing discharge process from 100% to 0, which take a considerable amount of time to complete it. Power failure storage feature allows you to finish this process in one or more passes, as it accumulate capacity again when power on again. Up to 9 sets of data help you easily calculate the real capacity. Screen can be shut off during this process or at night for distraction-free experience. Wide Test Range & Simple Operation: Input/Output Voltage: DC3.6-30V, Current Range: 0-5.1A. Large range of USB meter makes it widely compatible with USB-A port devices such as mobile phones, tablets, laptops, car chargers, power , wall chargers, cables, etc. Color: Transparent Black Material: Aluminum Alloy Package Contents: 1 * piece USB test Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.