BINGPET Adjustable Leather Dog Muzzle Breathable Safety Pet Puppy Muzzles Mask for Biting and Barking XL mouth circumference 11.7-12.7 inch(tip of the mouth), 15.6-17.5 inch (middle of the mouth), 17.1-20.2 inch (sides of mouth around the back of head) This muzzles are made from strong, flexible leather and are designed to fit securely and comfortably on dogs' snouts. Each muzzle has an adjustable strap with a quick-release buckle,the leather loop in the back easily connects to the collar or leash. Protect your children when staying with dogs, also protect your dogs from eating leftovers in the street. This muzzles hard to move,offer a high level of safety when working with aggressive dogs.