In the context of SFP (Small Form-Factor Pluggable) transceivers, "LR" stands for "Long Range." SFP LR modules are designed to support long-distance optical communication. These modules are commonly used in networking applications where the transmission distance exceeds the reach of standard SFP modules. 

For SFP transceivers, the specific reach or distance capability is often indicated by a code appended to the SFP type. Here are some common SFP types and their corresponding reach designations:

• SX (Short Reach): Typically used for short-distance multimode fiber connections, supporting distances up to a few hundred meters.

• LX (Long Reach): Used for longer-distance connections over multimode or single-mode fiber, with a reach of up to several kilometers.

• LR (Long Range): Specifically designed for long-distance connections over single-mode fiber. LR modules can support distances of up to 10 kilometers or more, depending on the specific implementation.

• ER (Extended Range): Similar to LR, ER modules are designed for extended reach over single-mode fiber, typically supporting distances beyond 10 kilometers.

These reach designations help network administrators and engineers choose the appropriate SFP module based on the required transmission distance for their specific application. The choice between SX, LX, LR, ER, or other variants depends on factors such as the type of fiber optic cable used, the distance between network devices, and the specific networking requirements.