Martingale is the leading collar for dog training. Made from 100% nylon and a thicker weave, these collars are durable, comfortable, and adjustable, and offer reinformed stitching for longer wear and tear. What sets the Martingale apart is that it provides more control over the animal without the choking effect of a slip collar. A simple adjustment is all you need to let your dog he is being corrected. Less discomfort to him, means faster learning and a strong handler/ dog bond. We recommed you fit it to your dog's neck leaving 2 inches (2 finger width) of slack between the collar and neck.