Adult tennis racket head size oversize racket head size 658 cm head size inches 102 sq in stringing 16 x 19 playing properties control power balance 350 mm recommended height from 155 cm weight unstrung 255 g grip size l1 l3 frame material graphite shape oval frame profile min 23 mm frame max 27 mm length 686 cm length inches 27 technologies yonex new isometric yonex aero shape yonex ops yonex shockless grommet system yonex