Adult tennis racket head size midplus racket head size 632 cm head size inches 98 sq in stringing 18 x 20 level professional type of racket tournament racket balance 310 mm recommended height from 155 cm weight unstrung 320 g racket balance head light grip size l1 l5 frame material graphite shape oval frame profile min 21 mm frame max 21 mm length 685 cm length inches 27 technology head graphene season 2015 series head p