Herm Sprenger Prong collar is made of Stainless Steel with a side release Security Buckle. Just slide the grey tab on the release and push down on the button the buckle is open! Guaranteed against rust, tarnish, or breakage when used properly. Proper fit is achieved by adding or removing links -- just snap them in or out. This buckle collar is easy to put on and take off with the top release buckle. This is a "Ultra-Plus" collar with a center plate to allow for "constant impact" and "optimized communication with the dog". This collar produces an even pressured safe pinch for the most effective corrective dog training collar available. This is not a Martingale collar. The ends of the prongs are nicely rounded and not sharp.
The collar should be worn snug on the neck it should be fit just under the jaw right behind the ears. Sizing: When measuring your dog , measure around the neck behind the ears.