Features 1.Comprehensive Testing Capability: The USB power meter allows you to test battery voltage, current, and discharge capacity. It has a maximum range of 99999mAh, providing precise and accurate measurements for your devices. 2.Communicate Functionality: The USB power meter is equipped with USB communicate capabilities on both the input and output terminals, allowing for easy data transfer. This B+B?D+D? four line connection ensures efficient and reliable communication. 3.Data Zeroing: By holding down the button until the display changes to the another data set, you can easily reset the data. The USB power meter can store up to 10 sets of data and automatically switches to the another set for zeroing. 4.Data Viewing: Double clicking the button within 0.5 seconds activates the data viewing mode. The backlight LED will flash, displaying the another set of data with each subsequent button press. To exit the data viewing mode, simply double click the button again. The backlight LED remains on to ensure clear visibility. 5.Voltage Alert: The USB power meter features a voltage alert system that warns you of high or low voltage levels. When triggered, the backlight LED will flash, accompanied by an audible alert. Pressing the button will keep the LED on for 30 seconds, allowing you to easily monitor and address any voltage issues. specificationItem Type: USB Power Meter_x000D_ Material: PC Shell_x000D_ Interface: USB2.0_x000D_ Test Content: Battery Voltage, Current, Discharge Capacity Maximum Range 99999mAh (10 sets of data in total) PackageList1 x USB Power Meter