New 2008 model Meets all Bat Performance Standards - ASA, USSSA, NSA, ISA, SSUSA and ISF When the girls ask for it, DeMarini delivers. Introducing the Fastpitch 375: born from the same version of the Slowpitch bat, the 375 launches bombs with DoubleWall technology made of DM1 Alloy, a Softball select alloy maximizing the trampoline effect for 375 lbs. compression softballs. Doublewall - Two independent walls create dynamic springboard hitting surface with maximum trampoline effect DM1 Alloy - specifically developed for regulation softball bats. DM-1 high-strength alloy maximizes the trampoline effect when hitting 375-pound compression balls. Positack 2 - Improved DeMarini exclusive made of moisture-absorbing composite material which delivers an even better grip and reduces vibration and hand fatigue for better feel and control. Flex Index 4 - The flex index shows a general scale of flexes available on bats. Typical all-aluminum bats flex less, giving the player a harsher feel & less performance on off-center hits. DeMarini Half & Half bats flex more (lower flex index) giving the player increased power, a better feel & more confidence on off-center hits. Rotation Index - The DeMarini Rotation Index helps players significantly prolong the life of DeMarini bats. A numerical index on the handle reminds players to incrementally rotate the bat after each hit, distributing wear around the entire barrel.