Metal Wire Basket Dog Muzzle Boxer, Bulldog Medium. Circumference 13.5", Length 3.5" Light, durable, comfortable, and safe. Very well ventilated Ideal solution for grooming, off-leash walks Allow for panting and drinking, dog will not have hard time breathing during the training. This size is particularly suited for dogs like medium size Boxer, Bulldog or other breeds with similar snout structure. Circumference 13.5", length 3.5" (from the tip of the nose to the eyeline). Please, measure your dog's snout before you place the order to insure this is the correct muzzle size you need.