The Dunlop Pro are double yellow dot squash balls designed with professional, tournament and club players in mind who look for unmatched durability and playability ensured by the N-1SR Molecular Technology. These 40mm competition balls offer the lowest bounce in the range and are supplied as a 1 dozen pack (4 x 3-ball tube). They are the official balls of the WSF (World Squash Federation), PSA (Professional Squash Association) and WSA (Women\'s Squash Association).