2 5/8 Inch Barrel Diameter Drop 3 Length-To-Weight Ratio End Loaded Swing Feel Two-Piece, All-Composite Baseball Bat BBCOR .50 Certified For High School & Collegiate Play KNOB IS BUILT TO HOLD A BLAST MOTION SENSOR IN IT. WHEN SENSOR IS ADDED TO THE BAT YOU CAN EASILY ACCESS THE ANALYTICS OF YOUR SWING. **SENSOR SOLD SEPARATELY** Extended Inner Barrel - Increases The MOI (i.e. End Loaded Feel) Of The Bat.