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. 900 Global Cove Bowling Ball ? High Performance and Stability Take your game to the next level with the 900 Global Cove Bowling Ball, a powerhouse built for performance, stability, and smooth motion. Positioned just above the Zen 25 in the 800 Series, the Cove blends innovation and reliability with the RB85 Hybrid Reactive Coverstock and the Magna AI symmetrical core, giving you clean control and consistent reaction on medium to heavy oil conditions. Engineered for bowlers who demand versatility without sacrificing hook potential, the RB85 Hybrid Coverstock delivers responsive mid-lane traction and continuous backend motion. The Magna AI Core features a dual-hemisphere design that provides exceptional core stability and promotes a steady roll throughout the lane. With a 4000 Grit finish, moderate flare potential, and tuned-for-performance RG and differential values, the Cove is the ideal benchmark ball for seasoned league players and competitive tournament bowlers alike. Key Features: RB85 Hybrid Reactive Coverstock ? Offers a strong mid-lane read with dependable backend continuation Magna AI Symmetrical Core ? Dual-hemisphere core design for maximum balance and lane stability 4000 Grit Finish ? Polished surface for traction and consistent motion on medium to heavy oil Benchmark Motion ? Perfect for transitioning lane conditions or as a first-out-of-the-bag option RG/Diff (15LB) ? RG: 2.49 / Diff: 0.044 for strong overall motion and controlled flare potential Specifications: Brand: 900 Global Line: 800 Series Color: Blue / White / Teal Coverstock: Hybrid Reactive Cover Name: RB85 Hybrid Reactive Core Shape: Symmetrical Core Name: Magna AI Core Surface Finish: 4000 Grit Flare Potential: 4 ? 5 Inches Radius of Gyration (RG - 15LB): 2.49 Differential (Diff - 15LB): 0.044 Mass Bias Strength: N/A Recommended Lane Conditions: Medium ? Heavy Oil Available Weights: 12LB, 13LB, 14LB, 15LB, 16LB Scent: None