Adult tennis racket head size oversize racket head size 677 cm head size inches 105 sq in stringing 16 x 20 level beginner type of racket comfort racket playing properties power balance 340 mm recommended height from 155 cm weight unstrung 260 g racket balance even grip size l0 l4 frame material graphite shape oval length 685 cm length inches 27 season 2017 series babolat game babolat pulsion colours blue white additional i