Xcess C.O.R. means excess power and control. The coefficient of restitution (COR) is the measure of how much energy is transferred from the club head to the ball at impact. The Pyro Xcess C.O.R Driver possesses the upper limit of COR allowed. This powerful oversized Titanium driver utilizes a cup-face construction for unparalleled distance. The Pyro Xcess C.O.R is backweighted for superb high-launch characteristics which is ideal for the newest golf ball technology. Features a 57 gram regular flex graphite shaft.