The Black Knight Tru-Bounce double yellow dot balls are designed to meet the standards of the World Squash Federation. The balls feature the Tru-Bounce technology thanks to which they do not only match the speed of the conventional tournament balls, but also provide enhanced durability as well as more consistent performance than that of standard balls. The Black Knight Tru-Bounce have been used by professional players such as David Palmer. They are sold as a 6-dozen pack (6 x 12-ball box).