TPX Louisville Slugger SL12EX2 -9 EXOGRID 2. The Heart of the Game is in the crack of the Bat and the Heart of the Exogrid is the internal carbon composite sleeve that provides the stiffest handle on the market (20% stiffer than competitors). Metal is trimmed in the transition and is then replaced with composite inserts that are several times stronger and lighter than the metal they replace to provide an even stiffer handle. Combined with AC21 alloy and Exogrid2 technology, TPX has the stiffest hybrid bat handle on the market by 20%. Now 1/2 oz lighter vs. the 2011 model Exogrid toa -9 Wt. drop.