Herm Sprenger Prong collar is made of Stainless Steel with a side release buckle. These collars are 100% rust proof. This buckle collar is easy to put on and take off with the side release cliclock buckle. Herm Sprenger"s innovative design replaces the traditional wire eye link with a solid fastener plate that provides a more secure connection. This plus the security buckle makes fastening the collar around the dog"s neck much easier and safer. Finest quality precision crafted.