Callaway Tour IX Golf Balls The new Tour ix Golf Ball is the most technologically advanced and longest tour ball you've ever played. The breakthrough in distance comes from innovative 4-piece inertia technology. The technologically advanced Tour ix Golf Ball featured 4-piece inertia technology and dual core construction designed to optimize distance. The ball's high-density outer core moves weight away from the center of the ball for increased moment of inertia (MOI) resulting in reduced driver spin for increased distance and accuracy. The ball's dual core construction allows for great distance off the tee while still offering spin around the green. The lower compression inner core provides low spin off the driver for great distance while the higher compression outer core provides high chip-shot spin.