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. If you’re looking for a smooth and predictable reaction, the !Q Tour 78/U may be for you! We’ve been testing new urethane materials and the combination on this bowling ball creates a new reaction different than current urethane options in the bowling industry. The new Controll 78 Urethane is also PBA compliant. Color: Crimson Coverstock: Controll 78 Solid Urethane Core: C³ Centripetal Core Finish: 500-grit Abralon Flare: Medium RG: (16lbs) 2.49 (15lbs) 2.49 (14lbs) 2.54 (13lbs) 2.59 (12) 2.65 Differential: .(16lbs) .035 (15lbs) .029 (14lbs) .034 (13lbs) .045 (12lbs) .035