This 15 ball set is one of the most unique billiard balls on the market today. Each ball features a beautiful granite appearance, yet carry the same high level of quality you've come to expect with Aramith balls. Aramith balls feature:- Perfect roundness and balance- Uniform weight and hardness- Brilliant colors- Friction resistant roll and reaction. Aramith phenolic balls last up to five times longer than other balls made from polymers or polyester. Billiards-play simulators have shown that Aramith phenolic balls are still perfectly playable even after 400,000 hits, whereas others were rendered unusable