Zytree(TM)Stainless Steel Protractor Round Head Rotary Goniometer Angle Ruler Professional Measuring Tool Drafting Supplies Professional tool for drawing or measuring angles or lines. High-quality stainless steel material is durable. Round head protractor is double graduated from 0 to 180, ruler is graduated from 0 to 10cm. Adjust protractor by loosing screw. Package Size: 24 * 7 * 2cm / 9.5 * 2.8 * 0.8in