The Head Speed MP (18x20) features a standard length and closed string pattern for those players who want a crisper feel and more control. It features Head's YOUTEK technology that incorporates a new "smart material" into the frame called d3o. d3o is located in the shaft area where the racquet flexes the most and is able to sense the needs of the player during different strokes. On high impact strokes, the molecules lock together instantly to increase the stiffness of the racquet for more power. On slow speed strokes, the molecules absorb the impact to provide a softer touch for better feel. With d3o and Teflon Friction Reducing Polymer grommets, YOUTEK provides a perfect combination to match your individual needs. This frame offers the perfect combination of power and feel for heavy hitters with longer, faster swing styles. Recommended for 4.0-7.0 level players.