40GBASE-LR4 and OTU3 Multirate 10km Gen2 QSFP+ Optical TransceiverFTL4C1QM2C QSFP+ transceiver modules are designed for use in 40 Gigabit Ethernet links and 4x10G OTN client interfaces over single mode fiber. They are compliant with the QSFP+ MSA, IEEE 802.3ba 40GBASE-LR4 and OTU3 C4S1-2D1 requirements specified in ITU-T Recommendation G.695. Digital diagnostics functions are available via an I2C interface, as specified by the QSFP+ MSA. The optical transceiver is RoHS compliant as described in Application Note AN-2038.