Just when you thought it was safe to go shopping! De-de...De-de...De-de-De-de-De-de! These Shark costume accessory hats are a blast! They are 1-size fits all and look exactly as featured. Circumference of the hat opening is 22 inches. A good bet to win the prize at crazy hat parties and a great accessory for any aquatic theme! Great on its own and even better with other costumes or accessories found at our store!