Adult tennis racket head size midsize racket head size 613 cm head size inches 95 sq in stringing 16 x 18 level professional type of racket tournament racket playing properties spin balance 315 mm recommended height from 155 cm weight unstrung 332 g grip circumference 106 108 mm racket balance head light grip size l2 frame materials basalt carbon shape oval frame profile min 22 mm frame max 22 mm length 685 cm length inches