Adult tennis racket head size midplus racket head size 645 cm head size inches 100 sq in stringing 16 x 19 level advanced type of racket all round racket playing properties control power spin balance 315 mm weight unstrung 295 g racket balance head light stiffness 67 ra grip size l1 l4 shape oval technologies dunlop srx dunlop hybrid cross section dunlop glide polymer dunlop hyper flare dunlop parellel strung season 2017 series dunlop