Adult tennis racket head size midsize racket head size 600 cm head size inches 93 sq in stringing 16 x 21 level professional type of racket tournament racket recommended height from 155 cm weight unstrung 310 g shape oval length 685 cm length inches 27 technologies yonex 3d vector shaft yonex micro core yonex bt hybrid season 2015 series yonex vcore special feature compatible with smart tennis sensor colour red