Plus or minus 1percent , accurate measurement data. Input Voltage: 4V-30V, Voltage Resolution: 0.01V, Test Current: 0.05A-3.50A, Current Resolution: 0.01A, Capacity Range: 0-19999mAH. USB current detector has clear LED display, making it easy to monitor the charge voltage and current of your digital USB devices, while ensuring the optimal charge rate. Simultaneously displaying of Amp and Volt in real-time Intelligent memory charging capacity data, monitoring and memory measurement data, up to 10 sets of measurement data stored, the data can be a button to clear, the data self-protection is not lost USB current monitor can improve the charging efficiency, protect the electronic equipment, perfect measurement for the tablet, cell phone batteries, rechargeable treasure, 5V routers and any other 5V USB digital device operating current, voltage, and battery capacity Simultaneous display of voltage, current and mAH data for easy viewing Can detect mobile power output mAH Multi-group detection data storage, power-down storage function Input voltage: 3V-7V Accuracy: plus or minus 1percent Line loss: about 0.1 ohm Test content: battery voltage, current, discharge capacity (a total of 10 sets of data) Size: 5.8 x 2.7 x 1.9cm, cable length 20cm, with USB Colour: white Material: ABS Package Contents: 1 x Voltage detector Only the above package content, other products are not included. Note: Light 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.