Huawei QSFP-40G-LR4 is a carrier-grade QSFP+ transceiver designed for 40GE long‑reach single-mode connectivity up to 10 km. Operating over four CWDM wavelengths (1271/1291/1311/1331 nm) with LC connectors, it complies with 40GBASE-LR4 and industry MSA standards. An eSFP module is an SFP module that supports monitoring of voltage, temperature, bias current, transmit optical power, and receive optical power. The higher transmission rate an optical module provides, the more complex structure it has. The design is compliant to 40GBASE-LR4 of the IEEE P802.