Wilson US Open Tennis Balls - Extra Duty

The Wilson US Open Extra Duty tennis ball is the official ball of the US Open since 1978. The US Open tennis ball is made with exclusive felt from Tex Tech Industries for superior playability, consistency, and durability. The yellow, extra duty felt is made for hard court surfaces. Also available are Wilson US Open Regular Duty tennis ball for clay or indoor courts, Wilson US Open High Altitude tennis ball for all court surfaces over 3500 ft. elevation, or Wilson US Open Grass Court tennis ball with white felt. The Wilson US Open tennis ball is both USTA and ITF approved.