This bowling ball ships PRE-DRILLED. There are 5 sizes and the sizes that we drill are based on the weight of the ball. X-Small: 6lbs- Ages 8 and under, Small: 8lbs and 9lbs- Ages 8-11 and womens ring size from 8-11, Medium: 10lbs, 11lbs, and 12lbs, Ages 11-15 and Adult Ring size 10 or lower, Large: 13lbs and 14lbs, Mens ring size 10-12 or people with larger hands, X-Large: 15lbs and 16lbs, Mens ring size over 13 or people with extremely large hands. If you would like a different size drilled for the weight you selected, you must contact us via email as soon as your order is placed with your order number. Pre-Drilled bowling balls cannot be returned or exchanged. Hammer has been on a roll and is ready to continue the momentum with the Extreme Envy. Big hook and no stop on the backend; that’s Extreme Envy! The first Envy handled heavy oil easily, but bowlers have been asking for more pop on the backend, and we’ve delivered that with the new Extreme Envy. We started with the Envy cover and added carbon fiber; this addition has created a heavy oil ball that does not quit on the backend. Extreme Envy has a different core than the original Envy; this version of the Launcher core has a slightly lower RG and was created to match the Envy CFI cover perfectly. Everything about this new Envy is Extreme; you’ll be extremely happy with yours whenever you need lots of hook! Performance: High&; Color:Black/Crimson/White; Core: Launcher LRG Coverstock: Envy CFI SOlid Cover Type: Solid Reactive; Finish: 500, 2000 Solid Reactive Weights: 12-16lbs Lane Condition: Medium to Heavy Oil& Reaction: Strong Overall Hook; Warranty: Two Years From Purchase Date Radius of Gyration(RG): 16lbs - 2.493; 15lbs - 2.479; 14lbs - 2.52 Differentail (Diff): 16lbs - 0.046; 15lbs - 0.054; 14lbs - 0.054 Intermediate Diff: 16lbs - 0.019; 15lbs - 0.022; 14lbs - 0.018