Junior tennis racket head size midsize racket head size 613 cm head size inches 95 sq in stringing 16 x 19 balance 255 mm recommended height 104 116 cm weight unstrung 200 g grip circumference 100 102 mm racket balance head light grip size l0 frame material graphite shape oval length 534 cm length inches 21 season 2015 series babolat pure colour blue