Adult tennis racket head size midplus racket head size 632 cm head size inches 98 sq in stringing 16 x 19 type of racket tournament racket playing properties control power spin balance 315 mm recommended height from 155 cm weight unstrung 295 g racket balance head light grip size l1 l5 shape oval frame profile min 20 mm frame max 23 mm length inches 27 technology head graphenext season 2017 special feature with handle sensor