Adjustable Nylon Dog Muzzle No Bite 10"-13.3" Size Large, Black, Bullterrier, Boxer, Doberman, German Shepherd This size will fit for Large dogs. You should measure it right below the eyeline. This size generally most suitable for Large dogs like Bullterrier, German Shepherd, or other breeds with similar snout size and structure. Well-fitting, comfortable muzzle is made of high quality Nylon. Dog snout measurements: circumference 10"-13.3". Adjustable nylon straps wouldn't stratch.