Franklin Sports MLB Pro-Elite Thin Bat Swing Trainer...Improve Your Batting Skills! Franklin MLB Pro-Elite Thin Bat Swing Trainer helps strengthens swing speed and hand-eye coordination. Thin aluminum construction that is 30" in length and has a 1 1/8" diameter bat barrel. Includes (3) 5.5" Soft Strike mini balls. Improve Your Hitting With This Franklin Sports Thin Bat Swing Trainer!