Fit Flight Pro series was four year in the making and features grid lattice-like frame.  The thickest portion runs along the edge. The added thickness around the sides and at the shaft socket strengthens the flight and will decrease tears along its length.  By combining a medium thickness with the thinnest portion of the flight it creates the inner lattice work. This combination works to disperse external pressure. This decentralization of the external pressure has an effect not only on durability but also on shape retention which will greatly extend the usable life of the flight.