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. We’re Hammer, and we’re not going to do things like everyone else, thus, the Raw Hammer series. This pearl version is finished with factory polish, creating more length. The Raw Hammer line is complete with solid, pearl, and hybrid balls at different factory finishes to provide pro shops with the ability to fit bowlers into a Raw Hammer that fits their needs. All Raw Hammers contain the original Raw Hammer core and come in 10 through 16 pounds. The uniqueness is in the cover and finishes. COLOR: Black/Purple/Teal CORE: Raw Hammer COVERSTOCK: Juiced Pearl COVER TYPE: Pearl Reactive FINISH: 500, 1000, 2000 Siaair Micro Pad / Factory Polish WEIGHTS: 10-16 Pounds LANE CONDITION: Medium to light oil REACTION: Skid/Flip WARRANTY: Two years from purchase date