"Thanks to the extra thick core of natural rubber, the Chuckit tennis balls are extremely suitable for long-term use and therefore very durable. The high bounce capacity and the size - which allows the balls to fit in Chuckit Ball Launchers - greatly enhance the playtime fun for both you and your dog. Moreover, the Chuckit tennis balls float, so you can even retrieve them from the water without fearing to lose the ball! The Chuckit tennis balls are specially designed for dogs."