The unrivalled performance, durability and consistency are the reasons why Dunlop continues to be the World's No.1 squash ball. Dunlop is the official ball of the World Squash Federation (WSF), the Professional Squash Association (PSA), and the Women's Squash Association (WSA). Recommended Player Type: Intermediate Provides outstanding performance and great value for club play. This single yellow dot ball is the same standard size as the Pro ball, but has a 10% longer hang-time. Hang-time Advert All Dunlop balls are engineered with N-1SR construction technology, an elastic hydrocarbon polymer with 12 compounds to create a unique construction material that delivers unparalleled durability and playability.