pressure and friction

forms a seal with the surface

SPENCO® Performance Gel Heel Cups provide true heel cupping that gives extra cushioning and stability to the heel

Tennis ball comes deflated

Geared towards professionals

Wilson US Open Tournament Red Ball 24 Cans Brand_Volkl pressure and frictionLarger Wilson US Open Tournament Red felt tennis balls make them easier to hit for young players in training. The lower compression makes them the perfect choice for training on 36 courts, driveways, and playgrounds. Recommended for ages 8 and under. Low compression bounces 75% lower than standard balls. Adorned with a specific red dot and number branded. Great for use with a 21 23 racquet.