This protractor is made of materials and can be used for a long time. It is characterized by the use of plastic materials, which has high durability and is not easily deformed. workmanship to ensure practicality. The structure is simple and the operation is convenient. Features -Material: ABS -The swing arm can slide 360 degrees without dead angle, which is more convenient for teachers to show right angles and obtuse angles for students. -Fine workmanship, comfortable hand feeling, which won't hurt your hands. -This tool not only help student to learn angles, but also helps students to standardize drawing. -360 degrees of coverage in 1-degree : Various scales can offer a variety of readings. -It is a practical and stationery for pupils, and this will help they to learn the angles more easily. Package list: 3 x Plastic 360 Degree Protractor