KT21-7 KT21ACET28A19.2 KT21ACET28A19.2M KT21A-DCV28A19.680MT/3.22.5 KT21A-DCV28B19.200MT KT21A-DCV28B-19.200M-T KT21-DCV28-30.000M-T KT21-DCV28N-19.800M-T KT21D-DCV28A-19.200M-T KT21D-DCV28C19.200MT