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. Another exciting release for Hammer is an innovative polyester ball, a Black Widow Viz-A-Ball… with the Gas Mask core! This exciting ball provides the hitting power and flare the core offers and takes the Widow polyester line to the next level with full Black Widow images. Spare balls with a performance core have been popular for bowlers who want a harder-hitting spare ball or a ball for extremely dry lanes. Never before has a Viz-A-Ball featured a high-performance core, and there’s no better core or line to launch such a fantastic product. PERFORMANCE: Polyester PART NUMBER: 60-106686-93X CORE: Gas Mask COVERSTOCK: Polyester COVER TYPE: Polyester FINISH: Crown Factory Polish WEIGHTS: 16-12 Pounds LANE CONDITION: Light oil REACTION: Straight WARRANTY: One year from purchase date 16 lb 15 lb 14 lb 13 lb 12 lb RG 2.510 2.500 2.500 2.589 2.612 DIFF 0.048 0.058 0.056 0.043 0.043 ASY 0.015 0.016 0.016 0.011 0.011