This ball ships professionally PRE-DRILLED for your convenience. We?ve simplified the process so you can hit the lanes faster. Based on the ball weight you choose, we?ll drill it to a standard hand size that fits most bowlers in that weight range: X-Small (6lbs): Ages 8 under Small (8?9lbs): Ages 8?11, women?s ring size 8?11 Medium (10?12lbs): Ages 11?15, adult ring size 10 or under Large (13?14lbs): Men?s ring size 10?12 or larger hands X-Large (15?16lbs): Men?s ring size 13+ or extra-large hands Want a different drilling size than standard? Email us immediately after checkout with your order number and your preferred size. Storm Equinox Solid Bowling Ball You love the Equinox, and now it?s back with even more hook. Introducing the Storm Equinox Solid, a bold, aggressive high-performance ball designed to dominate medium to heavy oil conditions. Built for competitive bowlers chasing strong midlane traction and explosive backend motion, this ball combines cutting-edge core dynamics with Storm?s next-generation cover technology. At its core is the revolutionary Solarion A.I. Core. Featuring a tri-cylindrical asymmetrical design, it delivers fast revving action, torque, and continuation. With an RG of 2.48, differential of .054, and mass bias of .018, it creates aggressive flare potential while maintaining consistency shot after shot. Paired with the brand-new A2S Solid Reactive coverstock, the Equinox Solid pushes the boundaries of oil absorption and traction. Its 2000 Grit finish digs into the midlane while still producing a sharp, angular backend rarely seen in solid covers. The result is a versatile and powerful motion that gives bowlers the edge in competition. Key Features: Built for medium to heavy oil lane conditions A2S Solid Reactive coverstock for enhanced traction and responsiveness Solarion A.I. asymmetrical core design for explosive motion RG 2.48, Diff .054, Mass Bias .018 for high flare potential Aggressive midlane read with strong backend continuation Available in weights 12?16lb Bold Black/Green/White colorway with Cherry Apple Slush scent Specifications: Brand: Storm Coverstock Type: Reactive Coverstock Name: Storm A2S Solid Reactive Core Shape: Asymmetrical Core Name: Storm Solarion A.I. Core RG (15lb): 2.48 Differential (15lb): .054 Mass Bias Strength: .018 Flare Potential: 4?5 Inches Surface Finish: 2000 Grit Lane Conditions: Medium ? Heavy Oil Performance Level: High Performance (Storm Premier Line) Color: Black, Green, White Weights: 12lb, 13lb, 14lb, 15lb, 16lb Scent: Cherry Apple Slush