The Track Proof 15lb 4oz Reactive Bowling Ball is a high-quality ten-pin bowling ball designed for serious players. Made of durable urethane material, this undrilled ball features an asymmetrical core for improved performance on the bowling lane. Weighing 15 lbs, it meets the standards set by the United States Bowling Congress (USBC) and is perfect for competitive play. The sleek design and advanced technology make it a top choice for bowlers looking to improve their game.