This set features 15 regulation pool balls and an Aramith oversize cue ball. Top Quality Aramith balls feature: - Perfect roundness and balance - Uniform weight and hardness - Brilliant colors - Friction resistant roll and reaction When you make an investment in Aramith balls, you can be assured you are getting one of the highest quality ball sets on the market. Aramith phenolic balls last up to five times longer than other balls made from polymers or polyester.