Swing Trainer - MediumThe Swing Trainer Medium Works well for bowlers using a 10, 11 or 12 lb ball Weighs approximately 3 lbs The Swing Trainer: Straighten arm swing Promote straight back, straight forward swing Loosen arm swing for a smooth gravity fed swing A wobble in the back or in the front of the swing means you are grabbing or muscling Work on hand position and staying behind the Swing Trainer throughout the swing Improve balance and core strength The Swing Trainer