Get in the groove with this blue and red pearl Brunswick Power Groove bowling ball. The Power Groove Reactive balls are made with 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.