Material: The angle measuring ruler is made of high quality stainless steel. The surface of the product is smooth, smooth, scratch-resistant, wear-resistant and rust-proof, and can be used for a long time. Unique Design: The two-in-one stainless steel square ruler can not only accurately measure the angle in the range of 0-180, but also measure the length from 0-140mm easily and quickly. EASY TO USE: The metal protractor can rotate the protractor 180 degrees by adjusting the nut, and can lock the ruler in the desired position at a fixed angle, making it quick and easy to measure the angle. Wide range of applications: protractors are important tools in many fields, commonly used in machinery, crafts, construction engineering, construction and maintenance engineering, etc., and can be used in homes, offices and schools.