Penn’s pressureless balls help slow the game down for those just learning how to play. The 12 pressureless balls are packed in a mesh bag with drawstring for easy transport and storage. The best-selling tennis ball in America, Penn is the standard by which all others are measured. An ideal tennis ball for those looking for a casual practice session, Penn Pressureless Tennis Balls are great for players looking to fine tune their game. Long-life pressureless cores offer extended play value with Penn quality you know you can trust. Gender: unisex. Age Group: adult.