Measuring range: 4*90°\r Accuracy: 0.1 Product: Electronic Digital Spirit Level\r Working temperature: 0-50°C\r Material: Aluminum alloy\r Power supply: 2*1.5V AAA\r Automatic power off: 5 minutes\r Resolution: 0.05°\r Calibration procedure\r 1 When the power is on, place the product on the work surface, press the ON/OFF+H/L button at the same time. The \"---1---\" icon will appear on the LCD screen,\r 2. Press ON/OFF, the \"---1---\" icon will flash for three seconds, and then \"---2---\" will appear,\r 3. Rotate the device 180° horizontally, then press the ON/OFF button and \"---2---\" will flash until the angle reading is visible, the calibration is complete\r \r BUTTONS\r < 1>ON/OFF\r In the off state, short press it to turn on the power; then press this button for 3\r seconds to turn it off.\r * After 3 minutes without movement or button press, the power will be turned off.\r ZERO\r When the product is running, short press the \"Zero\" button and it will directly enter\r relative angle measurement (the screen will display \"REF\"). Long press this button will change the state to absolute angle measurement and \"REF\" will disappear.\r H/L\r If you need to measure the angle in an unreadable position or want to lock the reading while recording it. Simply press the H/L button when the product is on. Press it again to turn it off. When the backlight is off, long press H/L to turn on the backlight.\r Otherwise, when the backlight is on, long press H/L to turn off the backlight.\r \r Package includes: 1*Digital Spirit Level\r \r Note:\r 1. Due to the difference between different monitors, the picture may not reflect the actual color of the item.\r 2. Please allow slight dimension difference due to different manual measurement.