Wonderswing Speeder,golf Swing Aids, Swing Trainer,increase Head Speed Swings 20 plus miles per hour faster than your own driver. Activates the fast twitch muscle fibers through over-speed training effect. Hear, See and Feel the proper release with the one-of-a-kind Magnetic Sliding Timing Ball: eliminates casting and coming over the top for the perfect release every time Recognized by top players on the PGA Tour as the fastest way to increase club head speed. Add 21-30 yards in carry distance with your driver after only 6 swings with the Speed Whoosh