Important tips when choosing a zipper Because the zipper has different adaptability in different environments, it should be specially proposed to the manufacturer when purchasing the zipper: First, what kind of products the zipper is applied to (such as luggage, shoes, ski clothes, Raincoats, tents, denim that requires washing, or more acidic leather goods) or other special requirements. Second, the requirements of the zipper component, whether it needs to contain no azo (AZO), does not contain nickel, or can pass the needle detector. Third, 3#, 4#, 5# These are the numbers of the zipper, which are measured by the width of the zipper after closing. Simply put: the bigger the number, the thicker the zipper. Usually the zippers on our jackets are all 5#, like 8# and 10#, which are special zippers, very rough, special order, usually less used. 4YG refers to the zipper on the trousers, which refers to the zipper of the 4# YG head. The zipper head is locked, especially on jeans and slacks. It is relatively strong and is generally metal. Most of the branded clothes will be custom-made zipper cards on the zippers of their clothes, usually in different shapes, and the brand LOGO is engraved on it, which is a very detailed thing. If done well, it will become a sign.