The Lepawit 8 Pack Cat Feather Toys Colorful Rainbow Flutter Balls with Feather and Bells Interactive Chaser Teaser Toy for Cats Kittens is a great way to encourage your cat to exercise. These balls are made of lightweight and high quality plastic, which makes them flexible and perfect for playing and chasing. The set includes 4 colors of balls in green, blue, yellow and rose red, as well as 2 inch diameter balls.