Adult tennis racket head size oversize racket head size 671 cm head size inches 104 sq in stringing 16 x 19 level beginner type of racket all round racket balance 325 mm recommended height from 155 cm weight unstrung 310 g racket balance head light grip size l1 l5 frame materials carbon glass fibre shape oval frame profile min 24 mm frame max 24 mm length 693 cm length inches 27 technology vlkl organix season 2013 serie