Ultra blue racquetballs. America's No. 1 selling racquetball, the standard by which all other racquetballs are measured. Bright blue color for added on-court visibility. Clear plastic, foil-sealed container with screw-top lid for safety and improved recycling. Made of optimized rubber compound for consistent playability and increased durability. Official ball of the A.A.R.A. for added retail promotion. Penn double performance guarantee: If any Penn ball should fail before the label wears off, Penn will replace it with 2 new balls.