Whether you bowl for cash or just for fun, the straight-shooting, durable Ice Storm is so cool your biggest rival will have a meltdown! Coverstock Pearl Polyester. Ball Finish 3500-grit Polish. Durometer 85-87 Rex D-scale Fragrance: None. Weight Block Traditional 3-piece Core. Radius of Gyration 2. 69 (High) Differential . 010 (Low). Flare Potential 1" (Low).