Adult tennis racket head size oversize racket head size 658 cm head size inches 102 sq in stringing 16 x 19 level beginner type of racket all round racket playing properties comfort power balance 325 mm recommended height from 155 cm weight unstrung 280 g racket balance head light stiffness 70 ra grip size l0 l4 frame material graphite shape oval length 685 cm length inches 27 season 2017 series babolat game babolat strike