Louisville Slugger TPX Exogrid CB9X High School / College Baseball Bat ST+20 Alloy One Piece Aluminum Frame Exclusive Exogrid Bi/Fusion Process-Using a combination of heat and extreme pressure, the sleeve inserts and metal wall are bonded to function as a single solid unit Internal Carbon Composite Sleeve-The heart of the Exogrid CB9X is the carbon sleeve which provides greater handle stiffness than aluminum alone ever could. Unidirectional fibers run the full length of the handle Carbon Composite Inserts-Metal is trimmed in a grid pattern, then replaced with carbon composite inserts that are several times stronger and lighter than the metal they replace The result is a stiff handled bat. A stiff handle produces more barrel flex, resulting in maximum trampoline effect and ultimately, greater performance. Patented Pro Cup end cap Synthetic Grip 2 5/8 inch barrel -3oz length to weight ratio 31/32 inch tapered handle Model CB9X replaces previous models CB71X and CB82X