Set the Magnetic Sliding Timing Ball at the grip end of the shaft to develop the proper timing and release during the swing.  As you make practice swings with the Speed Whoosh, the magnetic timing ball will give you immediate feedback as to whether you’re casting the club, (releasing the club head to early), or releasing the club head at the ideal time. If you cast the club, the Magnetic Sliding Timing Ball will release from the grip too early and hit at the end of the shaft before impact. Bought new for $129.98.