1000Base-BX Bi-Directional SFP Modules are designed for long-distance Gigabit Ethernet applications over singlemode fiber. This group includes complementary 1310nm/1490nm and 1490nm/1310nm transmit and receive configurations, with support for transmission distances up to 120 km. These modules provide a practical solution for extending Gigabit network connections while using wavelength-separated bi-directional communication.