Western FreeSpace Girth. 
 
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 engage by the use of an unimpeded Rectus Abdominus and better leg retraction due to the Ascending Pectoral muscles not being squashed!
 
The girth is made from a synthetic leather that you will have to look hard to notice the difference.  The reason we use synthetic material is because of its' superior qualities of keeping clean and looking great even after years of use.
 
With traditional Western, rounded, stainless steel buckles, surrounded by extra padding for optimum comfort. 
 
WHICH STERNUM PLATE SHOULD I PICK?
You should measure between the area between the front legs at the point where the elbows are parallel as the girth sits just behind the front legs but extends to the point where the elbows are.
 
The Standard Sternum Plate measured at the point it lies just between the back of the elbows of the horse, is 7.25 inches (18.5cm) wide.
 
The Slim Sternum Plate is for horses that are narrower between the front legs.. Measured between the front legs, at the point where it lies just between the back of the elbows of the horse, the slim version is only 4.5 inches wide (11.5cm) so would be better suited for the slimmer horse.