In aluminum bat construction, the alloy's strength is key to bat design, performance, and durability. A proprietary alloy heat treatment process developed by Louisville Slugger research and development engineers and Alcoa's Tech Center gives Warrior a new level of strength, making it the strongest and most advanced alloy ever introduced by Louisville Slugger. Warrior's cutting edge toughness and strength have allowed Louisville Slugger to design a bat with the ultimate combination of balance, sweet spot, performance and durability. Louisville Slugger senior league bats are specifically designed for players between 13 and 15 years of age as well as younger players whose leagues allow bat diameters largest than 2 1/4". All senior league bats have the Major League Baseball logo on the barrel. Warrior alloy 3-Compartment air-pressurized chamber 2 3/4" patented full barrel Patented pro cup end cap Synthetic grip, 7/8" standard handle 05