Enjoy hours of fun with the Aerobie Sonic Fin. The adjustable fins can be adjusted for maximum distance. Aerodynamically designed to travel up to 90 metres. The Aerobie Sonic Fin makes throwing spirals easier for kids. The Aerobie Sonic Fin Football whistles when it flies, adding to the fun. Compete against your friends to see how far you can make the Aerobie Sonic Fin.