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. Columbia 300 dominated the 90s with the most popular and best-performing bowling balls, and the brand has recently created a niche by modernizing those products for today’s environment. The Power Torq, Messengers, and Cuda’s have all done extremely well, they perform great, and bowlers love nostalgia. The Piranha line was unquestionably one of Columbia 300’s most popular lines, and we’re excited to bring back the name and original core shape with a few tweaks. The core is a dynamic two-piece core with the PowerCOR ball inside and has a high differential for more flare and hook. The Piranha PowerCOR features HK22 as a solid and is sanded at 2000; this cover and finish will give bowlers an advantage on any medium to heavy condition SERIES: High - Piranha PART NUMBER: 60-108047-93X COLOR: Blue / Navy CORE: Piranha PowerCOR COVERSTOCK: HK22 - ERT+ Solid COVER TYPE: Solid Reactive FINISH: 500, 2000 Siaair Micro Pad WEIGHTS: 16-12 Pounds LANE CONDITION: Medium to heavy oil REACTION: Strong overall hook WARRANTY: Two years from purchase date RG (16lbs)2.527 (15lbs)2.518 (14lbs)2.533 (13lbs)2.582 (12lbs)2.605 DIFF (16lbs)0.048 (15lbs)0.055 (14lbs)0.055 (13lbs)0.042 (12lbs)0.042