100% pure poly 40+ training ball. With consistent roundness and an excellent bounce, this is by far the best 100% poly training ball we have tested. This ball will slide through even the pickiest table tennis robots with ease, and is perfect for multi ball training as well. It should be noted this ball is not a "reject" of the 3 star poly ball manufacturing process, it is specifically made to mimic the weight and feel of a true 3 star poly ball without the cost. Although this ball has a 1 star stamp, in order to "upgrade" to a better poly ball you have to jump up to a 3 star to get a noticeable performance increase.