The Nike Sumo² 5900 driver has pushed the moment of inertia (MOI), volume and efficiency to the limits of what U.S. Golf Association rules allow. This squared driver has a convex crown and much deeper face than most drivers, increasing ball speed off impact and allowing the ball to fly more accurately. The face of the club is multi-layered from corner to corner, allowing faster ball speed off every part of the face and providing more distance even on off-center hits. The Aldila, Nike or UST brand shaft can be provided with a senior, regular, stiff or extra-stiff flex shaft, along with a Nike rubber composition grip for comfort. Though Nike has since exited the club manufacturing industry, the Sumo² 5900 is still available on the secondary market.