Semperfi-the on you have pictured is for BB. The one for SB is slightly longer. It is good for warming up but will add it will help build up arm speed. It's also good helping arm stay long through the hip. If the windmill is improper you will know it in seconds when it's wobbling all over and you hit yourself in the legs. Been to a few camps that will use a long sock w/weighted ball to achieve same purpose.