The zipper is composed of zipper fabric and zipper teeth. According to different zipper teeth, it can be divided into metal zipper, nylon zipper and dew zipper. The teeth of the metal zipper is metal, this kind of zipper has the advantages of high occlusiveness, durability, high grade but high price. It is mostly used for leather or other high-quality products. The teeth of nylon zipper are mainly made of nylon, which is the most popular zipper at present. The teeth of the dew zipper are thick and special in appearance, but its durability is not as high as the other two. It is mostly used for products with a certain style.