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 Storm Tropical bowling ball legacy continues with the Surge core making a great bowling ball for entry level and casual league bowlers. The bright fun colors and unique fragrances make these fun balls appealing to bowlers of every skill level. Each ball features the Reactor Pearl Reactive coverstock that glides through the front of the lane, reacts down-lane, and creates optimum pin carry. The Surge core has a higher differential which brings dependability and a little more hook at the backend. Color: Gold/Purple Coverstock: Reactor Pearl Coverstock Core: Surge (12#-16#) Finish: Reacta Gloss Recommended Lane Condition: Light to medium oil Flare Potential: 2"-4" (medium) RG: 16#-2.57 15#-2.58 14#-2.60 13#-2.62 12#-2.64 Differential: 16#-.025 15#-.024 14#-.025 13#-.021 12#-.020 Fragrance: Red Hot Cinnamon