Ultraball dog ball featuring a super high bounce. Better than standard tennis balls, the Ultraball is made of durable rubber yielding an ultra bouncy, exciting fetch experience on land or on water thanks to lightweight, bouyant design. Compatible with Medium Chuckit Launchers. This 8-pack of Chuckit balls for dogs includes a self-draining Chuckit Bucket which can also be used to both transport and clean the balls after playing a game of fetch. This rugged dog fetch toy has a textured surface and a thick rubber core that can stand up to rough play yet is soft on dog's mouths. Measures 2.5 inches diameter and is best suited for dogs weighing 0 to 20 pounds.