I purchased a dozen cans simply because of price -$2 each. These all court balls have a thicker felt than the regular Wilson or Penn balls, and feel heavier . However they are not as hard as the regular Dunlop tennis balls, and really lose their bounce after a few games of play on a concrete tennis surface. They lack durability, and felt lumpy. One of the cans that I purchased were flat, reflecting quality control in the sealing of the can container, or that the balls were simply too old. I will not purchase these again.