... optional DDM(digital diagnostic function) optional Hot-Pluggable SFP footprint Duplex LC Connector Metal Enclosure, Excellent EMI & ESD performance RoHS ... for part number: Part NumberDescriptionASFP1G-40-S31-C1000BASE-EX 40km SM 1310nm SFP, without DDM, 0 ~ +70 °CASFP1G-40-S31- ... with DDM, 0 ~ +70 °CASFP1G-40-S31-I1000BASE-EX 40km SM 1310nm SFP, without DDM, -45~+85°CASFP1G-40-S31-ID1000BASE ...