Characteristics HIGH QUALITY MATERIALS - The goniometer is made of high quality ABS material which is lightweight and easy to handle. It comes with a brass locking nut for sturdiness and stability. PRACTICAL DESIGN - You can lock the adjustable protractor arm to the desired position with the knurled thumb nut for quick and easy angle identification, if you feel the screw is too tight or too loose, you can adjust the screw before using the protractor. Construction Protractor - This protractor has a 0 to 180 degree semicircular scale that measures all angles on a job both forward and backward. You can also convert odd angles to your miter saw. VERSATILE - This plastic protractor measures inside and outside mitre angles and marking angles. MULTIPURPOSE PRECIPITATOR - The plastic protractor is great for construction work, cabinet making, fine woodworking or drafting. Product Name: Angle Protractor Product Material: ABS Product Size: As shown Colour: yellow Packing list (available after purchasing one product) Angle protractor *1 Please understand: 1.Due to the long shipping time, the item may be damaged during shipping. If the item is damaged, please leave us a message through the official website immediately and then post a comment, I will solve the problem for you. 2. Due to manual measurement, the size may have 1-3cm error. 3. Colour may vary by monitor.