Wilson's [K] Four FX features improved control due to new FX technology that includes the Quad Shaft, an innovative shaft design that distributes weight to four pillars instead of two. This provides improved control and exceptional torsional stability on off-center hits. It was designed for players who are beginning to utilize more pace and spin in their shots. This lightweight frame offers impressive stability and maneuverability thanks to Wilson's [K]ompact Center and [K]ontour Yoke design. It has a generous sweet spot and features a 107 sq. inch head size for more power. The open string pattern provides easy access to spin and plenty of pop. The extended body provides extra reach and power. Recommended for 3.0 to 5.0 players.