The Pro Power Drive Pivot Brace is the Only product of its kind. The Pro Power Drive Pivot Brace was designed at the request of MLB players that had the habit of breaking down on the back side/back knee/ankle that would caused them to swing up on the ball which made them hit pop ups. What the Pro Power Drive Pivot Brace does is it makes you stay tall on the back side/leg which keeps your hips & shoulders level. You Never want to collapse your back knee inward. It’s all about “Proper” Weight Shift, Balance, Staying Tall on the Back Side and Driving that Power Forward. By it making you do this, it is giving you the feel and teaching you Proper Muscle Memory to have the Proper Feel and Swing.