Adult tennis racket head size midsize racket head size 632 cm head size inches 98 sq in stringing 16 x 19 16 x 16 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 685 cm length inches 27 technologies head graphenext head asp adaptive string pattern season 2017 colours orange black additional information t