Size Reference: 3pcs 3 sizes. Small: 63.5x63.5x5mm/2.5x2.5x0.2", inner diameter: 50x50mm/2x2". Middle: 120x120x5mm/4.7x4.7x0.2", inner diameter: 101x101mm/4x4". Large: 185x185x5mm/7.2x7.2x0.2", inner diameter: 152x152mm/6x6inch Most Applicable: the measurement unit at the bottom is inch, and the centimeter is marked on the left, which makes this ruler apply to most tailors and handicraft producers. Premium Quality: Made of high -quality wood, the surface is smooth and without burrs. The thickness of 5mm is much strong and durable, which can improve efficiency for a long time. Perfect 90 Degree: They can not only measure, but also easily create 90 angle handicraft products. It is essential to ensure the balance of the project. Multifunctional: Clearly marked and multi-functional, you can quickly determine the needle number and yarn size. A perfect multifunctional sewing knitting tool for everyday life.