1. Timing shutdown settings. Continue to click the button until the screen display appears on the right. Then press and hold the button for 3 seconds, the numbers on the screen will flash. Click the button again to increase the 30-minute shutdown delay. Then press and hold the button for 3 seconds to save your settings.2. Overvoltage protection settings. Continue to click the button until the screen display appears on the right. Then press and hold the button for 3 seconds, the numbers on the screen will flash. Click the button again to increase 0.5 volts. Then press and hold the button for 3 seconds to save your settings.3. Overcurrent protection settings. Continue to click the button until the screen display appears on the right. Then press and hold the button for 3 seconds, the numbers on the screen will flash. Click the button again to increase 0.5A current. Then press and hold the button for 3 seconds to save your settings.4. Return to the main page, press and hold the button for 3 seconds to clear the saved data such as accumulated working time, , and energy.5. Current and voltage calibration : Please use 5.000V standard voltage. Press and hold the button until "Factory Settings" appears on the LED screen. It will automatically calibrate.1. Voltage: DC 4V-30V (overvoltage protection can be set)2. Current: 0-5.5A (overcurrent protection can be set.)3. : 0-150W4. : 0-99999mAh5. Energy: 0-999.9mWh6. Timing: 0-99 hours7. Countdown: 0-24 hours8. Charging : 0-999.999. Current/Temperature10. Data output voltage11. supply voltageMaterial:plasticcolour:WhitePackage Contents:1 x Voltage Current TesterOnly 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.