It replaces four SFP+ modules and internally contains transmitter and receiver for 4x 10Gbps over up to 10km single-mode fiber G. The four 10G data channels are transmitted over the CWDM wavelengths 1271, 1291, 1311 und 1331nm. Suitable for 40 Gigabit Ethernet or Fibre Channel. QSFP 40G LR4 is the preferred 40G optical transceiver for single-mode links up to 10km, offering a balanced solution between transmission distance, cost, and deployment flexibility. It is specifically designed for data center interconnects, enterprise backbone networks, and service provider. 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.