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, simple to measure and read. Power Supply: CR2032 3V lithium battery, with automatic power-off function, low power consumption, extending battery life. Lightweight and Durable: Thickened and widened ruler made of high-strength nylon fiberglass material, excellent 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 Off Time: 6 minutes