GameWear Super Bowl 2015 Champions Reflective Football Collar Neck Sizing Chart:Toy fits 8 - 12 inchesSmall fits 10 - 14 inchesMedium fits 14 - 20 inchesLarge fits 18 - 26 inches^Reflective Material - keep your pet safe^Get your favorite four-legged friend in the game with these officially licensed products from GameWear!!