Kalmar "junior featherweight" aji ne mai nauyi a cikin ƙwararrun dambe. A cewar Ƙungiyar Ƙwallon Ƙwallon Ƙasa ta Duniya (WBA), iyakar nauyin wannan aji shine fam 122 (kilogram 55.34). Kalmar “featherweight” tana nufin ajin nauyi da ke faɗuwa tsakanin super bantamweight da super featherweight, kuma “junior” yana nuna cewa ƙananan nauyi ne a cikin wannan ajin. Ma'ana, junior featherweight ajin nauyi ne a dambe wanda ya hada da mayakan da ba su wuce kilo 122 ba.