Your dog will have the best birthday paw-ty ever dressed up in the Celebration Hat and Collar set! Make sure they’re properly dressed for the occasion with the cutest dog birthday party hat. This set comes with a party hat with a multicolored balloon dog pattern and a matching collar with pom poms. The S/M hat has a 13-inch adjustable elastic strap and the elastic collar adjusts from 8 - 16 inches to comfortably fit medium dogs, small dogs and cats. The L/XL hat has a 13-inch adjustable elastic strap and the elastic collar adjusts from 17 - 25 inches to comfortably fit most large dogs.