The Chuckit! The Whistler Ball Dog Toy in size Medium is the perfect addition to any dog's toy collection. This 2.5" dog ball is designed with four sound holes that create a whistling sound, making fetch more exciting for dogs. With the recommendation of using any size Medium Chuckit! launcher, this toy is guaranteed to provide endless hours of entertainment for both you and your furry friend. However, it should be noted that casually tossing The Whistler will not yield loud whistles. To achieve the maximum effect of the whistling sound, it is important to use a launcher. In addition to the exciting whistling sound, this Chuckit! ball for dogs is made of durable rubber that yields an ultra-bouncy, exciting fetch experience. And with its super high bounce, The Whistler is perfect for dogs who love to run, jump and play. It is important to note that The Whistler is not designed to float and should only be used on land. As with all Chuckit! toys, it is not a chew toy, and you should always supervise your dog when playing with this toy. Size matters when it comes to dog balls, and the Chuckit! The Whistler Ball Dog Toy Size Medium measures 2.5" in diameter and is best suited for dogs weighing 20-60lbs. It is important to choose a dog ball that is small enough for your dog to carry but large enough that the ball can't completely fit in their mouth. When in doubt, it is always best to buy a size up. Overall, Chuckit! Performance toys are designed with you and your dog in mind, and The Whistler Ball Dog Toy is no exception. This toy is just one of the many options available in their full range of indoor and outdoor interactive dog toys including tumblers, flyers, fetch toys, other balls for dogs, and more. Chuckit! makes indoor and outdoor dog toys that enrich the human-animal bond and helps dogs and puppies stay engaged. With the Chuckit! The Whistler Ball Dog Toy, fetch just got a lot more exciting!