On the break, the cue ball can reach speeds of 20 mph in a fraction of a second creating massive surface temperature, which can cause burn spots and table cloth wear. The Aramith Crown Standard Belgian Pool Balls are constructed of Cast-Phenolic Resin, allowing them to withstand these high temperatures thus minimizing burn spots and table cloth wear. These 2 1/4" billiard balls weigh 6 ounces apiece and feature the number in the field as opposed to the stripe.