Ruler and protractor combination: measure length and angle with an accuracy of 0.3. This protractor is suitable for DIY projects, woodworking, decoration, and machining. 360-degree measurement: The hinge mechanism of the angle ruler allows a full 0-360 degree range for measuring inside and outside angles. Large LCD screen: Large full-screen LCD display, easy operation with only three push buttons, enables simple measuring and clear reading. Power supply: CR2032 3V lithium battery, with automatic power-off function, designed for low power consumption and extended battery life. Lightweight and durable: Thickened and widened ruler made of high-strength nylon fiberglass material, offering good rigidity, wear resistance, and no deformation. Hold function: LCD display features a hold function for convenient reading. Battery model: CR2032. Power supply: 3V. Operating time: 5000 hours. Automatic screen shut-off time: 6 minutes.