Simply put, Callaway Golf engineers have re-invented tour golf ball performance. This isn't a small step forward. It's a giant leap forward. 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. A tungsten-infused outer core to shift weight away from the center of the ball, reducing driver spin for maximum distance and straighter shots. The soft core formulation provides tour level feel and the urethane cover generates excellent short-game spin. A refined HEX Aerodynamics pattern further increases distance through reduced drag and better stability. 4 pieces, 2 cores, 1 unbeatable ball. This may contain a mixture of different year models.