As a youth coach, I spend a considerable amount of time correcting bad habits developed by young players over their early years of play. One problem that I have addressed is the that of an upper cut swing of the bat caused by using a batting tee. The batting sleeve solves this problem.
Power is created by bat speed and arm extension using the batting sleeve.
That is only one of the benefits provided. There is no batting tee to interfere with the play at home. The player uses the proper swing of the bat as opposed to an uppercut swing needed off the batting tee. The player sees immediate results with full arm extension. The coach can be close enough to the batter to correct even the smallest defect in the stance , grip , and swing .