According to the zipper thickness, it can be divided into 3#, 5#, 8# and 10#. The larger the number is, the thicker the zipper is, and the stronger the tension is. Zipper is used according to the size of the bag. For general size bags, such as backpacks and handbags, 5# zippers are basically used. For smaller products, such as wallets, 3# zippers are used. For large tool bags, 8# or 10# zippers are used. No. 5 zipper is a widely used zipper with the most colors and varieties.