The Vollint Mini Red Felt tennis balls are designed for teaching children the game of tennis. They are ideal for play on a 36-foot court and have a low compression core and a durable two-tone acrylic felt to allow for keeping track of spin development. These Stage 3 junior balls are larger (75mm) and 75% slower than standard tennis balls to give more time for preparation and help kids learn to hit the ball effectively. The balls are suitable for training and offer a lower, predictable bounce. They are recommended for children ages 4-8 and come in a handy mesh bag for easy storage and transportation to the court. The balls are supplied in a pack of 5 dozen (60 balls).