This dog crate is designed to gently guide the dog's head and then control the direction of the dog's movement (similar to a horse crate). The collar prevents your dog from pulling on the tow rope and reduces unwanted pulling, jumping or sprinting behaviors. You don't have to try too hard for their behavior. For you and your dog, walking without a collar is safer and more enjoyable. Durable and practical - the dog head cage is made of durable nylon and heavy stainless steel. Securely sewn head cover for medium and large dogs or dogs with heavy tow cords. This pet collar has an auxiliary tow rope that can be attached to a dog collar or tow rope. Reflective stripes on the dog's collar help keep the dog safe day and night. Comfort and safety - the padding of the nose ring is soft enough not to affect toughness, so that very comfortable dog's neck can prevent the skin from scratching your dog. When worn for long periods of time, the cotton pad still prevents the edge of the belt from abrading the dog's nose. It relieves pressure in the dog's throat, prevents the dog from choking or vomiting, and allows the dog to bark, breathe, eat or drink water. Adjustment easy - these dogs are equipped with quick release buckles with non-pull collars so you can wear them on your dog in minutes. The length of the strap is adjustable so you can choose the most comfortable length for your dog. This dog training leader will also provide a free training guide to help your dog adjust. Dimensions: Mouth: 11.6 inches - 14.8 inches, collar: 16.8 inch x 21.1 inch choose soft tape or ruler, measure 1 inch below eyes, close mouth, then measure neck circumference.