We commissioned the service of hardware engineers to create this essential piece of equipment, the Grit & Steel Bulldog Swivel. Using custom molds and 304 stainless steel we designed a through-the-collar swivel specific to the requirements of athletic, powerful dogs. This swivel accommodates all collars that are 2 inches wide (or smaller). Intended for adult dogs that weigh over 30lbs. There is not another swivel in the world that comes close to the thoughtful design, strength and durability of this piece; allowing you to enjoy years of secure, convenient, and reliable service.