Multifunctional Four-in-one Tool Pen Ruler Drawing Ruler Set Features: You can draw various circles as needed, these tools can be used in mathematical geometry and artistic architectural drawing, helping you to complete the work quickly. The math 's four-in-one function is suitable for math equations, geometry, art design, sketching, drawing and other fields. The drawing is for drawing circles and measuring angles, suitable for students, teachers, engineers, designers, artists, etc. The design incorporates multiple functions. Can also be used as a pen, ruler and eraser. No installation required, just the guard bar and it's to use. Made of ABS, the won't bend or deform during use, and is ergonomically designed for a comfortable grip. Product Description: Product material: ABS Product size: 13 cm long/ cm long Product function: suitable for mathematical equations, geometry, art design, sketching, drawing and other fields. Scope of use: school, home improvement woodworking, home. Package content: pen ruler