Just to say that at first I was quite sceptical of this aid but having used it and seen what it encourages a golfer to do I would say its really useful

Its KEY point for me is encouraging the player to set his wrists early and get the club up and behind quicker, literally zipping the club around the body. Most people you see try and keep that left arm straight and go 'low and slow' in a misguided attempt at width where this thing helps you get the feel for getting the club set and on-plane far quicker by using a connected body turn rather than a long and disconencted arms led takeaway