The Chuckit! Is one sweet way to exercise your dog without wearing out your arm. Made of lightweight, durable plastic, the Chuckit! uses a standard-size tennis ball and is designed for hands-free pickup so you NEVER have to bend down and pick up a slimy ball again. Use it in the park, in your backyard, or anywhere else with plenty of room. With a little practice you can consistently throw the ball 100 to 140 ft. The Ultra has a premium ultra grip with ergonomic handle and comes with an ultra buoyant, high bounce, durable natural rubber ball that easily washes off the slobber and dirt. Mega is 26" long. Mega Ball is an oversized tennis ball. Features Ultra Ball is compatible with the Jr. and the Original Chuckit! Mega Ball is an oversized tennis ball. Satisfaction Ensured Your Pet will Love it. Makes for a great Gift.