The Gamma Tennis Quick Kids Low Compression Foam Balls 12-Pack are designed specifically for teaching younger children the game of tennis. The bounce is lower and slower than a kid's tennis ball, or starter foam balls, allowing children to be more successful at hitting the ball while learning. to a standard tennis ball that makes an easier target for beginners. These foam balls conform to the USTA Schools Tennis Program standards for beginner foam balls (ages 8 and under).