Head YouTek Graphene Instinct MP Tennis Racquet The Instinct MP offers plenty of punch with excellent feel. This revolutionary design allows you to generate more power with less weight and less effort. Used by Maria Sharapova and Thomas Berdych. Headsize: 100 square inches / 645 sq. cm Weight (unstrung): 10.6 oz / 300 grams (strung): 11.1 oz / 315 grams Balance (strung): 3 points head light / 33 cm String Pattern: 16 Mains x 19 Crosses - Racquet is strung with synthetic gut and ready for use.