Sturdy nylon webbing and brass hardware make a fashionable duo in our classic martingale style collar. Martingale collars have a loop of webbing where the leash attaches, which causes the collar to tighten gently when the leash is pulled. It should fit loosely on the neck, providing more comfort for your dog and more control for you. This safer alternative also prevents your pup from backing out of their collar during walks, and avoids too much pressure on the trachea that can be caused by regular collars. Perfect for dogs who pull on leash, flight risk dogs, and dogs with wide necks. XXS (3/4" wide): neck size 9"-11.5" XS (3/4" wide): neck size 11"-15" small (1" wide): neck size 11"–15" medium (1" wide): neck size 14"–18" large (1" wide): neck size 17"–23"