Dunlop Pro Squash Ball - Double Yellow Traditional-sized black ball for professional, advanced and team players. This remains the official ball of the WSF, PSA, WISPA and Squash Canada, endorsements which ensure that Dunlop is the only ball used in all international professional competitions. The Pro is identified by a double yellow dot. Squash balls come in six varieties, each with different levels of bounce. A double yellow dot squash ball has a slow bounce with very low speed (hang time) and is recommended for experienced squash players. When choosing a squash ball the temperature of the court, altitude of the court, your opponent's skill level and of course your skill level all play a part in determining which squash ball to use. Contact us to help you pick the right squash ball today!