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. The dictionary defines a Game Breaker as a bowling ball that always performs and is one of the best values in bowling. The new Game Breaker 5 does not disappoint and will remind bowlers of the Game Breaker 4, but with more continuation. The new GB5 has the same storied core that has carried the popularity of the series and is paired with GB 12.7 Solid. The Game Breaker series has been missing the stronger cover intended for more traction and hook in oil, and that is precisely what you get with the new GB5! Color: Royal Blue/Dark Blue Core: Enhanced V2 Coverstock: GB 12.7 Solid Cover type: Solid Reactive Finish: 500, 1500 Siaair Micro Pad Weights: 10-16lbs Performance: Mid Reaction: Strong Overall Hook Lane Condition: Medium To Heavy Oil Warranty: 2 Years from purchase date RG: 16lbs (2.491) 15lbs(2.480) 14lbs(2.517) 13lbs(2.574) 12lbs(2.597) 11lbs(2.769) 10lbs(2.800) Diff: 16lbs(0.041) 15lbs(0.048) 14lbs(0.048) 13lbs(0.040) 12lbs(0.040) 11lbs(0.002) 10lbs(0.002)