Combat B4 8-Ounce Portent Senior Baseball Bat PMT (Precision Molded Technology) allows Combat engineers to design barrel wall thickness to maximize barrel trampoline effect and bat performance BFT (Blended Fiber Technology) is used to create more trampoline effect without sacrificing durability SBT ( Separation Barrier Technology) allows brand new bats to exhibit maximum performance and feel, right of the rack with no break-in period necessary-Hot Out of the Wrapper LST (Localized Stiffening Technology) achieves the absolute maximum performance and durability at every point along the barrel MMC (Membrane Modal Control) allows composite construction to maintain the highest performance standards allowed for the life of the bat