Adult tennis racket head size oversize racket head size 652 cm head size inches 101 sq in stringing 16 x 16 level advanced type of racket all round racket balance 320 mm recommended height from 155 cm weight unstrung 300 g racket balance head light frame material graphite shape oval frame profile min 20 mm frame max 22 mm length 687 cm length inches 27 season 2014 series prince tour