This D-ring isolator will install on a 3/4" shackle and is made from a tough and durable Polyurethane. To use this D-ring, just snap it in place. It takes only moments to install or remove it. This D-ring uses Polyurethane to insulate the shackle so that when your vehicle is in motion it won't touch your bumper or other point. It adds protection to your bumper to keep the D-ring from scratching its finish.