The Penn Natural Rubber Championship Extra Duty Tennis Ball Case is an excellent choice for tennis players seeking durability and high performance. Each case includes 12 cans, containing a total of 36 extra duty tennis balls, designed to provide a consistent feel and reduced shock thanks to their natural rubber construction.These tennis balls are official equipment for USTA league tennis, ensuring they meet the highest standards in the sport. The controlled fiber release technology used in their manufacturing process ensures a consistent nap, which translates to reliable performance on the court.Penn is a trusted brand known for its quality sports equipment, making these tennis balls a reliable choice for both amateur and professional players. The bright yellow color enhances visibility, while the included case provides convenient storage and protection for your tennis balls.Customer reviews highlight the longevity and performance of these tennis balls, with an impressive rating of 4.5 stars from 288 reviews. If you're looking for high-quality tennis balls that deliver consistent performance and durability, the Penn Natural Rubber Championship Extra Duty Tennis Ball Case is an excellent option.