Features: This small portable USB tester accurately monitors electric , current, power, and charging capacity in real time, helping users track charging position for phones and tablets with its high resolution LCD display. Featuring an very compact, U drive sized design produced of ABS and metal, it requires not batteries or external power, automatically working when plugged between chargers and device while supporting fast charges protocols like , , AFC, , and . Ideal for digital enthusiasts and repair technicians, this tool provides essential diagnostics for charging issues and accessory verification, catering to professional in device maintenance. Use it to evaluate charging efficiency in various scenarios, such as testing smartphone and tablet charging, power banks output, car chargers electric stability, and USB port power for practical applications. With its built in capacity meter that records total charging capacity in mAh or , this USB power monitor helps assess output performances and identify or degraded accessories reliably. Specifications: Component : ABS metal interfaces: USB Size: about 14x23.5x53mm/0.55x0.93x2.09inch Function: Detect mobile phone charging electric and current Package Includes: 1xUSB Tester note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.