Ubiquiti UniFi Single Mode 1.25G LC Bi-Directional SFP

The Ubiquiti UB-UF-SM-1G-S is a Single Mode SFP module designed for long-distance, outdoor fibre optic connections. This Bi-Directional (BiDi) module transmits and receives data over a single strand of fibre, ideal for maximising existing infrastructure and reaching distances up to 3km at 1.25Gbps. 
Key features:

Supports long-range fibre connections – extend your network up to 3km with reliable fibre optic connectivity
Bi-Directional transmission: Utilise a single fibre strand for transmitting and receiving data, maximising your infrastructure re-use. 
Single Mode fibre compatibility: Designed for use with single-mode (SM) fibre optic cables 
LC Connector: Features an LC connector for easy installation