Roto Grip RG Spare. The most durable, non-hook spare you can get, 16lbs. NEW IN BOX (NIB). Excellent ball just changing brands due to sponsorship. SHIPPING DISCOUNT GIVEN FOR MULTIPLE PURCHASES. The Roto Grip Retro RG Spare Bowling Ball is a high-quality, 16 lb ten-pin bowling ball made of durable urethane material. With a polished finish, this ball is designed for bowling enthusiasts looking for a reliable and long-lasting option. Backed by a 1-year manufacturer warranty, this Roto Grip ball is ideal for players looking to improve their game with a trusted brand like Roto Grip. Perfect for individuals seeking a spare ball to enhance their performance on the lanes.