This geometric ruler has multiple functions and a rotating central part, so it can also function as rulers of different shapes. What this geometric ruler can offer you is that it allows you to draw a variety of complex geometric shapes using just one ruler. It is made of plastic, which is durable for long term use. The length of the product is 12cm, the width is 12cm. It is suitable for classroom, school, office, home, etc. Item Name: Geometric Ruler Material: Plastic Color: Black, Blue Size Details: 12cm x 12cm/4.72" x 4.72" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Geometric Ruler