Lock screen function indication.The current moisture measurement reading.Current temperature reading.Power switch key.Switch between paper mode and wall mode.Wood type selection button.Lock screen key / Celsius & Fahrenheit switch button.Measurement instructions:1. Remove the battery cover, install 2 AAA dry batteries, press the power button once to turn on. This product has a blue backlight after it is turned on, which can be clearly displayed when the light is insufficient.2. Remove the electrode needle cap to expose the electrode needle.3. Press the "Wood" button to select the appropriate wood calibration scale A, B, C, D (please refer to the wood calibration table at the back of this guide) to measure the corresponding wood.4. Or press "Paper" or "Wall" key to select paper mode or wall mode. The paper mode is used to test paper/cardboard/carton. Wall mode is used to test thin slate/wall board/floor.5. Insert the needle into the material and read the currently displayed data. Press and hold the HOLD/C/F key once to lock the display reading.6. Read the current ambient temperature. Press and hold the HOLD/C/F key for 3 seconds to switch between Celsius and Fahrenheit.7. Press the power button once to turn off the power of the instrument.Electrode needle: integratedAutomatic shutdown: ater the button is not operated for 5 minutesPower supply: 2 AAA batteriesColour:blackMaterial:ABSPackage Contents:1 x Humidity Tester( no battery)Only the above package content, other products are not included.Note: Light shooting 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.