White polypropylene, Nickel-plated zinc single ended snap with Velcro. This is our most popular strap. Perfect for club and recreation facilities. With a revolutionary patented internal locking system, our self-measuring design for ease of installation, and high quality materials, this is the best strap on the market for the money. Sets up in under 60 seconds, and guaranteed not to slip. Courtmaster Tennis Equipment 106-753E