Size Reference - Binding base: 225x31x20.5 mm / 8.86x1.22x0.8 inches, hole: 3 mm thick. Please refer to picture 2 for more details Material - The book trimmer is made of bamboo, sturdy and durable, the surface is polished smooth and burr-free, feels comfortable and does not hurt your hand, easy and safe to use Practical Tool - The hole punching tool is designed to make it easy for you to punch holes in the text paper you need to collect, which makes the holes evenly spaced and prevents them from being punched crooked Easy to Use - The holes on the perforation guide are evenly distributed for easy identification, allowing you to focus on bookbinding and saving time Wide Application - This book binding kit can not only be used for book binding, but also can be used to punch holes in fabric or leather material fabrics, can be used to make sample kits, suitable for book binding DIY