Adult tennis racket head size midplus racket head size 632 cm head size inches 98 sq in stringing 16 x 20 level professional type of racket tournament racket playing properties comfort control power balance 310 mm recommended height from 155 cm weight unstrung 320 g racket balance head light stiffness 67 ra grip size l1 l5 frame material graphite shape oval length 685 cm length inches 27 season 2017 series babolat pure strike