The Penn Pressureless Tennis Balls (12 Balls) will help you take your skills to new levels. You can use them at home or on the court when you are ready for play. They are also ideal for use with tennis ball machines. Being pressureless, these balls come in handy for practice as they maintain their bounce longer and work consistently on all surfaces. They are preferred by coaches and instructors. On the whole, these pressureless Penn tennis balls are value-priced accessories made for recreational play. They are durable to ensure they hold up against use. The tennis ball pack will help you take your game to a whole new level.