CandyPet Martingale collars are collars made up of two nylon straps, in our case lined on both sides with cotton fabric (to minimize chafing with the neck), and joined by welded metal buckles. In addition, they have reinforced seams for greater strength. Uses a semi-choke system, with the advantage that does not hurt the dog due to the width of the collar. Also known as "Anti-Escape Collars", because it is almost impossible to escape a properly fitted Martingale It is ideal for breeds of dogs that have a head as close to the neck, such as greyhounds or potenos. But they can be used perfectly on any breed of dogs.