The Aramith 2-1/4" regulation size training cue ball was developed by American Professional Pocket Billiards player Jim Rempe, who was inducted into the BCA Hall of Fame. This cue ball is marked with rings and targets on the surface of the ball, allowing you to practice judging the effects of very particular amounts of sidespin, topspin, backspin and other forms of cue ball control. Intended to help players of all skill levels improve their game; one side of the cue ball is designed for beginners, and the opposite side provides instruction for advanced players. It's crafted from the highest quality phenolic resin which provides exceptional scratch and impact resistance. Each billiard ball adheres to the most stringent specifications in the industry, ensuring superior playability and durability.