Standard Nylon Muzzle - 3 1/2" for Dogs up to 5 pounds An expanded line of quick release muzzles. Safety - Muzzles fit securely with quick adjusting straps for a snug fit. Comfort - Lightweight nylon feels and looks more professional than gauze roll. Quality - Reinforced stitching to assure long lasting use. Available in 18 sizes. Snout circumference is the best measurement for determining muzzle size. For dogs up to 5 lbs - 3.5".