Junior tennis racket head size oversize racket head size 671 cm head size inches 104 sq in stringing 14 x 16 balance 280 mm recommended height 116 128 cm weight unstrung 220 g grip circumference 100 102 mm racket balance head light grip size l0 frame material graphite shape oval frame profile min 23 mm frame max 23 mm length 584 cm length inches 23 series prince warrior