SFP (Small Form-Factor Pluggable) modules typically use LC (Lucent Connector) connectors for fiber-optic connections. The LC connector is a small, high-performance connector that is widely used in networking and telecommunications applications.

Key characteristics of LC connectors for SFP modules include:

1. Size: LC connectors are small in size, contributing to the compact form factor of SFP modules.

2. Duplex Configuration: LC connectors are duplex connectors, meaning they have separate connectors for transmit (Tx) and receive (Rx) fibers. This is suitable for bidirectional communication, which is common in SFP modules.

3. Fiber Type: LC connectors are compatible with both single-mode and multi-mode fibers, allowing flexibility in the types of optical fibers used with SFP modules.

4. Latch Mechanism: LC connectors typically have a latch mechanism that secures the connection, ensuring stability and minimizing the risk of accidental disconnection.

5. Performance: LC connectors provide low insertion loss and high return loss, making them suitable for high-performance optical communication.

It's important to note that while LC connectors are common for SFP modules, there are other connector types used in different optical transceiver modules. For example, MTP/MPO connectors are used in some high-density applications.

When connecting SFP modules, it's essential to use the appropriate fiber patch cables with LC connectors on both ends to ensure proper optical connectivity. Always refer to the documentation of your networking equipment and SFP modules for the specific connector and fiber type requirements.