1' & 1.5' inch Wide Side Release Dod Collar Adjustable Side Release Collars are often referred to as a Humane or Soft Choke Collar. Side Release feature a side opening design that works by being tight around your dog's neck whenever it tries to remove it's head from the collar Made with Nickel Plated Hardware. Heavy Duty PolyPro Webbing. Fabric Cotton Covered. Side Release Buckle Material is Acetal. Acetal Resins are among the strongest and stiffest of all Thermoplastics.