Easy to install, just hook it on. Sold as a set of 2. Size: Width 2.8cm, Height 3.8cm We have a large number of zippers for sale. Discounts are available for bulk purchases, so please consider. a-11 *Due to difficulties in adjusting the lighting during photography, the color of the actual product may differ from the photos depending on the viewing environment and monitor resolution. There may be minor scratches or imperfections from the manufacturing process. Please be aware of this beforehand.