Storm Bowling Balls. TEN IN THE PIT! With the introduction of STORM's exciting new JOLT and JOLT Pearl comes a newly developed and dynamic weight block. Combining the world class ACCU Tread™ coverstock and innovative multi density weight block ensures a strong, consistent reaction every time. Coverstock Accu Tread Solid ReactiveWeight Block Modified 2 PieceBall Color PurpleTurquoiseBall Finish 1500 grit PolishLogos Jolt, Storm, Eye of the Storm CGDurometer 75 77 Rex D scaleFlare 3 Med LowFragrance Blueberry