This Mr. Pen 3 Piece Large Triangular Ruler Set is designed to equip architects engineers artists designers students and teachers with the right tools for various projects. It includes 11 30/60 and 8 45/90 triangles set squares a geometry ruler and BluePrint scale rulers. Each piece in this architectural scale ruler set is made of high-quality plastic for durability and the 12 architect triangular scale is made of plastic that is shatterproof. The 12 architect triangular scale also has graduations to the foot in 3/32 3/16 1/8 1/4 1/2 1 3/8 3/4 1 1/2 and 3 increments. This set helps you get the job done more effectively.