Adult tennis racket head size oversize racket head size 690 cm head size inches 107 sq in stringing 16 x 19 level beginner type of racket comfort racket playing properties comfort control power spin balance 330 mm recommended height from 155 cm weight unstrung 270 g racket balance even stiffness 69 ra grip size l0 l5 frame material graphite shape oval frame profile min 23 mm frame max 26 mm length 69 cm length inches 27