【Professional Protractor】 The protractor has passed our rigorous testing to ensure precise accuracy. The protractor's accuracy is ±0.2° and its measuring range is 0-360°. The folded length of the protractor is 200 mm/7.9 inches, and the total length is 400 mm/15.7 inches. 【Two-in-one Function】 The two-in-one combination of ruler and digital protractor can measure length and angle. It is ideal for woodworking, architectural decoration, mechanical processing, architectural drawing, home DIY, and school teaching tools. 【Button Functions】 ON/OFF/ZERO buttons (long press the OFF button to turn off), HOLD button for data locking (after locking, there is no need to worry about data deviation), D/M button. 【Lightweight and Portable】 Compared to stainless steel protractors, this measuring protractor is lighter and safer. The stable locking rotator can lock any angle of the protractor. 【Large LCD Display】 The angle ruler is equipped with a large LCD display, you can easily read the data and it is very friendly to vulnerable people. If the digital angle ruler is not used for a long time, it will automatically turn off to extend battery life.