Isomars Set Squares - Scholar - Set of 4 Drafting Rulers are combination of 10" and 12" professional triangles, Scale - 12" and Protractor - 6" (360 degrees) made of clear plastic . Set Squares are used in conjunction with straightedge of drawing board to draw accurate angles. Bevel Edge with Protractor. 25cm/10"- 45 degrees 30cm/12"-60 degrees Thickness - 2.5 mm. Markings on both side in mm/inch. Isomars Mechanical Pencil is designed for long-lasting use. Non slip grip for daily writing. It is the suitable tool for sketching and drawing. Superior drafting pencil for general and technical writing. Comes with eraser.