Item Type: Protractor Material: ABS+Stainless Steel Color: As shown in the picture Product Size: Approx. 6x5.6x2.4cm / 2.4x2.2x0.9in Weight: Approx.72g/2.5oz Battery: 2 x AAA battery(Not included) Measuring Range: 490 Resolution: 0.05 Operating Temperature: 0~40 Working Humidity: 40~80% humidity How to Use: 1. Absolute angle measurement Press ON/OFF, and the machine will directly enter the absolute angle measurement state (you need to load the battery directly when you turn it on). It will display the angle between the measured surface and the level. When the angle between the working surface of the unit and the horizontal plane changes, the angle value also changes. When the two indicator arrows on both sides of the LCD display appear, the working surface of the display unit is not on a horizontal surface. For example, when the arrow "" on one side appears, it indicates that this side is below the horizontal line. It needs to be moved to this side of the unit to reach the level. The arrow "t" indicates that it is above the horizontal line. When the working surface of the machine is on a horizontal plane, the two indicator arrows will disappear, 2. Relative angle measurement Place the working surface of the machine on the surface that needs to be preset, press the CALICARBATE button to display "0.00". Then move the measuring unit to another surface to be measured, and the displayed value is the angle between the two surfaces. Press the CALICARBATE button for 3~5 seconds, it will switch to the absolute measurement state 3. Upright display The displayed value will not be inverted, regardless of whether the unit is inverted or not.