Our colorful Target Rings attach to a tennis net with Velcro in just seconds to focus serving practice as well as many other shots, including passing shots, return of serves, and more. They can also be placed directly on the ground and used as court targets. The targets are made of impact-resistant nylon with a durable fiberglass frame. The opening is 6-feet in diameter. The Target Rings fold together into their own case for convenient storage when not in use.