Plastic slips. The Groove grips. And grip is exactly what you need to improve your game. When you're ready to step up from plastic, get in the Groove.Ready to start hooking the ball Move up from Plastic to Reactive coverstock technology. Compared to Plastic, Reactive coverstock technology increases traction and hooking action in the oil, and Reactive coverstocks can be sanded or shined to create large differences in hook potential. Reactive coverstocks also respond more aggressively to dry lane surfaces than Urethane coverstocks, increasing backend hooking action and hitting power.Coverstock These three Power Groove Reactive balls feature a factory polished version Brunswick's popular PowrKoil 17 Reactive coverstock. Factory polishing helpes create a more skidsnap reaction that saves most of its hooking action for the back part of the lane. First used on the Sapphire Zone, PowrKoil 17 is the strongest Reactive coverstock ever used on a Groove class ball.Core The Power Groove Reactive group feature Brunswick's DISC Differential Increasing Side Cylinders core technology which provides The largest track flare potential of any ball in its class.Consistent track flare potentials at all weights from 12 16 pounds.Larger, more consistent pin out distances at all weights from 12 16 pounds.A more driller friendly design. The precise geometric placement of high density side cylinders maximizes the increase in Track Flare Potential while maintaining dynamic symmetry for easy drilling. Blems are seconds due to a cosmetic blemish, but the specifications fall out of the 2 4 2 4 oz. range. There are a couple of areas that the ball would not meet some first quality manufacturing specifications i.e. core chip or engraving error. Blems will have an X stamped by the serial number. The label on the box is stamped X Blem.NOTE Due to the limited availability of Blems, X Outs, and Seconds pin placement and top weight are not guaranteed.Product Type Bowling Balls