Protractor is made of high quality stainless steel, durable and smooth surface, High quality stainless steel protractor can work many years. Protractor equipped with an adjustable screw. Easy to rotate and no need worry of hurting your hand. When want to set a specific angle, the adjustable screw can help a lot Protractor is suitable for many ways. Such as perfect for school, commercial, home, mechanical work, woodworking applications,hobbyists and so on. It can improve efficiency Protractor set is made up a 180 degrees protractor and a 200mm ruler. They was fixed together by an adjustable screw. The protractor not only can measure angle, but also can measure straight line. Overall Length – 200 mm / 20cm / Markings are deeply etched and black filled for easy readability and long life.