The RAP Hittable Training Sleeve - Ultimate Bat Protection - Live Batting, Extends Bat Life, Develops Swing Speed, and Reduces Vibration. The RAP combines proprietary ballistic infused material with taper and barrel weights that optimizes moment of inertia, for a revolution in live batting practice and training. Hitters will feel the vibration dampening technology synthesized with compression layering, for realistic ball flight and ultimate bat protection. Designed for Youth (8+) to Pro. Features: Adds + 4oz to the bat during live hitting (a 33/30 bat feels like a 33/34) The RAP fits all types of baseball bats (one size fits most bats).