The Herm Sprenger Stainless Steel Prong collar is one of the most recognizable and popular names in obedience training tools. A safe and effective alternative to choker collars, it puts even pressure around the neck, about every half inch, pinching the skin in a band. This collar does not apply direct pressure to the trachea, so you can train your dog with little or no tugging, jerking, or pulling. The addition of a center plate connector allows the middle link to be configured symmetrically, enabling the prongs to tighten in the same direction. Made of high quality German stainless steel, the size of this collar can be adjusted by adding or removing the links individually. The comfort version with ring and swivel offers highest flexibility between dog collar and leash due to the swivel.
Features:
Interlocking links, each link equipped with two blunt prongs
Slips over dog's head for easy on, easy off
Slightly beveled prong tips
Easy to increase or decrease in size
Made of high quality stainless steel
Additional links sold separately 
1 ring and 1 swivel, with ClicLock closure (stainless steel)
Stainless steel 
This collar is made of stainless steel. Each collar made of this material has a high-gloss surface. But it is not all. Stainless steel is the same composition of iron, chromium, silicon, nickel and carbon that make up traditional stainless steel products. The collar will not rust even in conditions of seawater or high humidity.