This new innovative patented design has a Active Cushion Sternum Plate that has two parts.  The outer is a reinforced plate that will not give under girth tension.  This is spaced away from the horse by the Active Cushion which holds the Sternum Plate away from the horse's rib cage.  The Sternum Plate makes the girth straps bridge the pectoral muscles and it is this lack of pressure that is the key to allowing the horse to to the Ascending Pectoral muscles not being squashed! Slim version available for narrow horses.