Mesee 2 in 1 Digital Angle Finder Protractor Ruler - Combines a ruler and protractor for convenient length and angle measurements. Metric and imperial units are laser-etched on the ruler edge - Features an LCD display for quick and accurate angle calculation. Clear digital readout ensures easy viewing, even in low-light conditions - 360-degree rotating design enables measurement of inside, outside, and reverse angles from 0 to 360 degrees - Equipped with a locking knob to secure the angle at any position. The hold button allows instant angle retention - Ideal for DIY projects, construction, woodworking, measuring, sketching, and drawing Specifications: - Material: Carbon Fiber + ABS - Auto power-off: 5 minutes Battery Installation: 1. Push the protrusion at the bottom of the LCD unit 2. Pull out the battery compartment 3. Insert the battery with the negative pole facing up and positive pole facing down 4. Reinsert the battery compartment. It is recommended to remove the battery if the device is not in use for extended periods Operation: - HOLD Button: Press to freeze the current angle reading. "H" appears in the upper left corner. Press again to resume measurement mode - ON/OFF/ZERO Button: Press to set a new reference point (zero) at any angle. Press and hold to power on or off - D/M Button: Switch between Degree and Minute display modes Package Included: 1 x Digital Angle Ruler