DeMarini SF8 Slow Pitch Softball Bat 13 inch znx alloy barrel: designed and manufactured by DeMarini with the strongest alloy allowing the pop needed for serious hitters C6 composite handle: this carbon composite is specifically designed for the single wall construction of the Sf8. The wider weave creates a trampoline effect when the ball makes contact with the bat - causing it to jump off the barrel 6mm grip and rock knob: new grip and more comfortable knob added for improved feel and design USSSA, NSA, ASA, and ISA approved