... device t fiber ethernet 1*TP+1*fiber port,single-mode ... fiber ports, Ck-if21 supports 2 TP ports 1 fiber ... ST connector, optional)Single-mode: 20, 40,60, 80, 120Km, ... .Descriptionunitif11-M1*TP+1*fiber port,multi-mode,2Km, ... if21-M2*TP+1*fiber port,multi-mode, ... if11-S1*TP+1*fiber port,single-mode, ... if21-S2*TP+1*fiber port,single-mode, ... fiber is optinal media converter industrial ethernet to fiber optical fiber ...