A 1.25G SFP module, SM (Single Mode), Single Fiber, 120KM, 1550/1310, LC Connector, supports long-distance data transmission up to 120 kilometers over single-mode fiber optics. It operates at 1.25 Gbps and uses a single fiber for transmitting at 1550 nm and receiving at 1310 nm, ideal for robust and efficient connectivity in telecom and enterprise networks.