Penn Control+ Green Tennis Balls Ideal for advanced beginning players ages 9+ who play on a standard 78?? tennis court. The Control + ball reduces speed by 25% for greater control and longer rallies. With premium high-visibility felt for exceptional durability, the Penn Control+ ball is also enjoyable for adults who require a slower playing tennis ball. All Penn QST products are USTA and ITF approved and endorsed by the USPTA.