(IMPORTANT) Sunglasses will NOT fit Flat nosed or Wide faced dog breeds such as Bulldogs, Boxers, Pit-bulls, Bull Terriers, Shar-Pei, Chow Chows, etc. Fits Most Medium Dog breeds (20lbs~40lbs) such as American Cattle dog, Cocker Spaniel, Dalmation, Welshi Corgi, Shiba Inu, Beagle, Border collie, German Pinsher, Scottish Terrier, Cannan Dog, Carolina dog, Australian Shepherd, Schnauzer, etc Retainer strap included