Marucci CAT 8 #MCBC8 BBCOR Certified -3 33-Inch baseball bat has a single piece alloy construction. This bat features Marucci AZ105 alloy material, MV/WD multi-variable wall design, and AV2 anti-vibration knob. Maruuci CAT 8 -3 baseball bat has a 2-5/8 barrel diameter. 12 month bat warranty is valid from initial date of purchase.