Teach your little tennis pro how to play with the Prince(R) Youth 2-Pack Foam Tennis Balls. Youth Tennis Balls 2-pack, UTSA Stage 3 transition tennis balls Best suited for ages 8 and under Rebound: 33-41 inches Reduced ball speed of 75% compared to a standard tennis ball Aids in swing technique development of young players Provides larger target and 4 stages away from standard, adult tennis balls