The unrivalled performance, durability and consistency of Dunlop Squash balls 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) and the Professional Squash Association (PSA). Item Dot Level Size Hangtime Bounce Pro Double Yellow Dot Advanced Standard Shortest hangtime Very low Competition Single Yellow Dot Club/Team Standard 10% longer hangtime Low Progress Red Dot Intermediate 6% larger 20% longer hangtime Medium Intro Blue Dot Beginner 12% larger 40% longer hangtime High All Dunlop balls are engineered with N-1SR³ construction technology, an elastic hydrocarbon polymer with 12 compounds to create a unique construction material that delivers unparalleled durability and playability.