Typically, 1G LX SFP modules are not optimized for multimode fiber (MMF) connections. They are primarily designed for use with single-mode fiber (SMF).
1G LX SFP modules are intended for use with single-mode fiber, and they can support longer distances compared to multimode fiber.
The reach of 1G LX SFP over single-mode fiber is commonly up to 10 kilometers (km) or more. Some specifications may indicate a reach of 10 km or 20 km.
The actual reach may be influenced by factors such as the quality of the fiber optic cable, connectors, and the overall optical link budget.
Environmental conditions, such as signal attenuation due to bends, splices, or other factors, can also impact the effective reach of the SFP module.