40GBASE-LR4 2km Gen2 Lite QSFP+ Optical Transceiver FTL4C1QL2L QSFP+ optical transceiver modules are designed for use in 40 Gigabit Ethernet links over single mode fiber. They are compliant with the QSFP+ MSA and are compatible with IEEE 802.3ba 40GBASE-LR4 up to 2km. 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.