Specification: 1.Input/Output Voltage: 3V - 30V, Voltage Resolution: 0.01V 2.Voltage Measuring Range: 0 - 5.1A 3.Current: Input/Output: 0-5.1A, Current Resolution:0.01A Accuracy: ±1% Line loss:0.1Ω Introduction: 1. USB male-input connected to the charger output port 2. key- Zero key, press 3-5 seconds after the screen is cleared 3. USB female- output terminal is connected to the USB port data 4. Input voltage display window: 3-30V accuracy: ±1% 5. Charging current display window:3-30V accuracy:±1% 6. Battery capacity display window: 0-999.99Ah 7. Quantity of electric charged display window: 0-999.999Wh 8. Battery power display window 9. Working time display window:0-24 h (in seconds) 10.Work time and power displayed after power off memory function 11.Communication function: Yes 12.Parameters adjusting function: Yes. DIMENSIONS: L65mm * W 24mm * H14mm 1 x pcs Mini USB Tester Meter 1 x Transparent Plastic BoxAriMax