If your furry friend is reactive to nickel and often suffers from skin irritations, he/she will enjoy this Herm Sprenger Curogan pinch collar.
The collar consists of a center plate, assembly chain, 2 O-rings and blunt prongs. The center plate promises an equal pressure distribution along the collar. Two O-rings serve for lead attachment.
The prongs are symmetrically arranged around the length of the prong collar which means less neck traumas. This 3.2 mm wire gauge pinch collar is foolproof obedience and correction training gear.
This prong collar is 23 inches/58 cm long. Thus, it will do for dogs with 21 inches/53 cm neck size. But you can easily customize the collar length by adding or removing links. For more discrete look hide the links under a special nylon cover.
How do I measure the neck size of my dog?
Please put a measuring tape closely to the fur right behind the ears and under the jaw.
Mind that two fingers should slip between the collar and the dog's neck. Or you can measure his neck and add two inches.
When the collar is on his neck it should allow you to slide two fingers under the collar and your dog's neck.
If there's extra room, you need a smaller size and you should remove links. If both fingers don't fit, the collar is too small and some links should be added.

This collar is made from curogan. One of the biggest advantages of this material is that it is anti-allergenic. No more rash and itching. Curogan is nickel free, so it won't rust too.
NOTE!
This curogan collar is advisable for dogs with any hair color and those canines who are allergic to nickel. This metal avoids a discoloration of light-haired pets, however some dogs (1 dog in 10) do react on curogan with a discoloration. If your dog reacts to a curogan prong collar with discoloration, consider a stainless steel one.