Professional Protractor The protractor has passed our rigorous testing to ensure more accurate accuracy. The accuracy of the protractor is ±0.2° and the measuring range is 0-360°. Protractor folded length: 200mm/7.9in, total length: 400mm/15.7in. Two-in-one function The two-in-one combination of ruler and digital protractor can measure length and angle. It is very suitable for wood processing, architectural decoration, mechanical processing, architectural drawing, home DIY, school teaching utensils. Button function ON/OFF/ZERO buttons (long press the OFF button to turn off), data lock HOLD button (after locking, there is no need to worry about data deviation), D/M button. Lightweight and portable Compared with the stainless steel protractor, this measuring protractor is lighter and safer. The stable locking rotator can lock any angle of the protractor.