Play like a Pro with the Dunlop Pro Squash Ball. The official squash ball of the WSF and PSA and the only ball used in professional international squash competitions. The Dunlop Double Yellow Dot Pro Squash Ball is the ultimate performance squash ball for professional, tournament and club players. An elastic hydrocarbon polymer is impregnated with 12 compounds resulting in a construction material with unrivalled playability and durability characteristics which make this Dunlop Pro squash ball The Worlds No.1 Squash Ball!