Badminton racket stringing 22 x 21 recommended stringing tension max 11 kg level advanced balance 310 mm weight strung 96 g gewichtsklasse 3u 85 89g grip circumference 8 26 mm racket balance balanced grip size g4 length 67 5 cm season 2016 series yonex duora serie additional information the offers may vary in grip sizes material graphite flex medium