10 in 1 Digital Display 4-30V DC USB Tester Current Voltage Charger Gauge Power Bank Battery Capacity Voltmeter Timing Detector Ammeter VoltmeterSpecification:Material: ABSProard: 0-5ANvoltage: 4-30VCass: 0-99 HoursPower: 0-150WPotency: 0-999999mAhIndoor Temperature: 0-80°CSrupe: 1-9 GroupMAh: 0-999999mAhMWh: 0-999999mWhCharging: Rolling Resistance: e, Traction on 0-999.9Omega; D Positive Voltage: 0-10VD Negative Voltage: 0-10V Size: 56.6*24.7*11.2mm/2.23*0.97*0.44'' Weight: 20g Color: White, Black Instructions:1: click the button to display the group charging data 1-9.2: press the button for 3s and take out the charging data set.3: double click the button, rotate the screen to view.4. Press the button for a long time, insert the USB interface to enter the voltage calibration:For example:(1) if the display (5.526V right arrow indicator), then double-click the button quickly. (2) if the display (5.528V indicator arrow up), you can click the button to increase the display voltage. (3) Double click the button quickly, if the display (5.528V down the Indicator Arrow), you can click the button to lower the display voltage. (4) Then quickly double click the button again, if the display (indicator arrow 5.526V right), then click the button again, the screen will show the current calibration! The system automatically performs the current calibration and automatically returns to the main function page when the calibration is complete. Note:1. Due to the different monitor and light effect, the actual color of the item may be slightly different from the color showed on the pictures. Thank you!2. Please allow 1-3cm measurement deviation due to manual measurement.1 x USB Tester