Features: Backlight control, you can turn off or turn on the backlight by short pressing the button Separate wiring terminals independently, simple wiring, no mutual interference No screw elastic connection, tightly pressed, no damage to the LCD Strong and weak current circuit board, strong anti-interference Round high-end VA LCD screen Specification: Operating Voltage: AC 30~500V Measuring range: 0.1~100A (external CT) Accuracy: plusmn;1% Display format: 10A: 9.99A 100A: 99.9A 100A: 100A Error adjustment step 1: Long press the button (about 3 seconds) until the digital digit on the screen flashes, then release the button; Step 2: The digital flashing means entering the error adjustment state, and the digits flashing cyclically, as follows: Digital low...digital middle...digital high...decimal point, flashing means current Adjustable digits, short press the button to adjust the value (digit 0-9 cycle, decimal Point shift); Step 3: After the adjustment is complete, press and hold the button (about 3 seconds), the screen displays PASS and returns to normal the interface is often displayed, indicating that the adjustment is successful. Package includes: 1 x AC Current Tester Note: 1. This product is suitable for indoor use and cannot be used outdoors. 2. This product is suitable for AC and cannot test DC. 3. This product is suitable for single-phase power frequency AC power grid, and not suitable for other waveforms. 4. The working voltage and test current cannot exceed the calibration range. 5. Be sure to wire correctly