Chuckit! The Whistler Balls WHISTLES WHEN THROWN: Chuckit!'s whistling ball is designed with four sound holes that create a whistling sound in the air, making fetch more exciting for dogs HEALTHY PLAY: For stimulating playtime that helps pets stay fit, the Chuckit! whistle ball encourages pets to leap and chase HIGH-BOUNCING BALL: Made from durable rubber, The Whistler fetch balls for dogs are designed to bounce higher and farther than standard tennis balls CHUCKIT! LAUNCHER COMPATIBLE: To make fetch even more exciting for pets, this Whistler Chuckit! ball fits a variety of Chuckit! Ball Launchers; dog ball launchers available for purchase separately DURABLE DESIGN: To hold up to rough play, the Chuckit! outdoor dog toy ball is made of rugged, long-lasting rubber EASY TO CLEAN: Smooth, rubber surface of the Whistler Chuckit! ball resists mess and allows pet parents to easily wash off dirt or slobber AVAILABLE IN VARIOUS SIZES: Chuckit'!s whistling dog ball is offered in small, medium, and large sizes, allowing a wide range of dogs to enjoy whistling games of fetch AVAILABLE IN 2-PACKS: For pet parents that like to keep an extra ball on hand during fetch, select sizes of Chuckit! whistle ball for dogs are available in 2-packs