The QSFP-100GBASE-LR4 is a 100 Gigabit Ethernet Quad Small Form-Factor Pluggable (QSFP28) transceiver module. 1 It’s designed for long-reach connections, utilizing single-mode fiber (SMF) and LC connectors. 2 This module operates at 1310nm wavelengths, enabling transmission distances of up to 10 kilometers. 2 It’s commonly used in data centers and service provider networks for high-bandwidth connectivity. 3