1.Nylon zipper Features: Nylon zipper is soft, smooth, bright and colorful. The most prominent features are light weight, thin chain elements, and flexibility. Among them, waterproof zipper is also a branch of nylon zipper. It is a nylon zipper that has undergone some special treatments: PVC film, TPU film, waterproof agent soak, coated waterproof zipper, and so on. Disadvantages: Polyester monofilament is easy to age, and the applicable range for high and low temperature is narrow. 2.Metal zipper Features: durable, soft, elegant and solemn. Disadvantages: Chain elements are easier to fall off and shift than other types of zippers. Due to the high price of raw materials, they are more expensive than other types of zippers. Among them, the aluminum zipper is worse than the copper zipper of the same model. But after the surface treatment, it has the imitation copper and multi-color decoration, because the price is lower than copper, its sales price has a certain competitive advantage. The quality of the backpack zipper is not only related to the quality of the backpack. The matching zipper and backpack style are more finishing touch. The small zipper has a great effect. Therefore, no matter you choose to buy or customize the backpack, everyone should pay attention not to overlook the choice of zipper.