The Flap Surcingle is a feature found only on the Pro Dressage. It is built into the bottom of the saddle's flaps and when tightened over the girth pulls the flaps of the saddle down strongly and securely into place.
A flap surcingle prevents flaps from riding back and allows the rider to take advantage of the suede covering and extra grip panel built into the bottom of the flap to develop a very strong and secure leg position.