Four Paws Quick Fit Muzzles are made of nylon and completely washable. The Quick Fit Muzzles do not have a lot of buckles that always need adjustments. Only one initial fitting is needed. Available in 9 sizes. Size Snout Breed 0 4 1/2" Teacup/Toy Breeds- Cavaliers, Miniature Dachshunds, Miniature Poodles, Yorkies 1 5" Extra Small Breeds- Jack Russells, King Charles Spaniels, Pugs, Standard Dachshunds, Westies, Whippets 2 5 1/2" Small Breeds- Beagles, Border Collies, Cocker Spaniels, Springers, Standard Poodles 3 6" Medium Breeds- Bull Terriers, Dobermans, German Shepherds, Retrievers, Setters, Staffordshires 3XL 10 1/2" Boxer type breeds- short snouts 4 8" Large Breeds- Bloodhounds, Danes Pyreneans, St. Bernards, Wolfhounds, Labradors 4XL 10 3/4" Extra Large dogs listed in size 4 5 8 1/4" Extra Large Breeds- Bull Mastiffs, Rottweilers, Large Boxers 5XL 10 1/4" Extra Large dogs listed in size 5 Product Style Size Quick Fit Muzzle Size 0 Quick Fit Muzzle Size: Size 4 Color: Multi-Color