Mizuno MaxCor -3 BBCOR Adult Baseball Bat - Royal & Black Barrel Diameter - 2 5/8" Patent Pending design creates additional spin for increased distance. - Hitting surface creates a wider circumferential sweet area. Aerospace grade aluminum alloy core used to strengthen the bat. Dynamic Damper transition piece from barrel to tapper absorbs vibration for better feel. Digi-Grip for great feel and durability.