Fast Photonics 40G QSFP+ LR4 Optical transceiver module are designed for 40 Gigabit Ethernet links over 10km single mode fiber. It is a cost-effective, low power optical transceiver with high port densities and compact size. It is operating on CWDM wavelength(1271nm/1291nm/1311nm/1331nm), compliant with the QSFP+ MSA and IEEE 802.3ba protocol. Digital diagnostics functions are available via the I2C interface, as specified by the QSFP+ MSA