1.Specifications and package includes:12pcs/24pcs/36pcs | 2.Background clips length: 20 cm/ 8 inches(Stretchable to 16 inches); Consist of stretchy cords, locking release tabs, hook-and-loop part and metal clip | 3.Feature: high quality elastic rope, hook&loop, easy to install, move up and down to adjust position | 4.Usage method:Just strap them onto the side of backdrop stand, clip them on side of the backdrop, and push the button or pull the string to make the backdrop tight | 5.Reduce backdrop creases, make backdrop smoother, suit for all types of stand and background supports