Intermediate players wanting some extra pop and effortless access to spin will enjoy the benefits from this racquet. An updated version to the K Factor K Four, this Wilson K Four FX Racquet features the same K Factor technology as its predecessor, as well as an additional technology: FX. FX utilizes "quad shaft" construction in the throat, which, according to Wilson, provides the racquet with 23% more torsional stability than traditional racquets. No longer available in two headsizes, the new KFour features a 107 sq. inch head, supplying plenty of power and a generous sweetspot. We found the 16 x 19 string pattern to provide a ton of spin, whether it be from groundstrokes or up at net. At just around 10 oz strung, the racquet was maneuverable and easy to swing. Our TW Playtesters found the racquet to be fairly stable from all areas of the court, even on off center shots. On serve, we liked the amount of spin generated as well as some noticeable power, due to its added 1/2 inch length. Players looking for an edge, yearning for some more power and spin should definitely give this stick a demo. The K Four FX isn't only an update to the K Four, but an upgrade as well. Recommended for player from NTRP 3.5 - 4.5