The zipper of the shoulder USB Backpack is generally rigorous and stylish in terms of business, so the shoulder USB Backpack basically uses the 5th zipper, which is exquisite and compact. When selecting a zipper, it is necessary to directly pull it up, and it is feasible if it is easy to pull back and forth. Then comes the waterproofness of the USB Backpack zipper, which is commonly used as a waterproof nylon zipper. Because the nylon itself does not absorb water, and the nylon material is developed, the main test method is the degree of compression.
The slider is actually one of the design features of USB Backpack. The USB Backpack is designed with a double-head design that opens and closes the backpack opening on both sides. It is easy to use, which reduces the long-term damage of the slider and lengthens the service life of the zipper. Shoulder USB Backpack's slider If you choose a plastic slider, check his firmness. If you choose a metal slider, check the metal density of the USB Backpack slider; if it is a silicone slider, check his toughness.