It is widely SFP 1.25Gb/s is designed for single mode

The SFP 1.25Gb/s transceiver modules are hot pluggable I/O devices that plug into module sockets. The transceiver connects the electrical circuitry of the module with the optical or copper network. GBIC transceiver, short name for the Gigabit Interface Converter, is a media conversion device between Gigabit Ethernet and fiber optic networks. Via the GBIC transceiver, Gigabit network equipment can directly connect to copper wires, single mode fiber ports or multimode fiber ports. SFP 1.25Gb/s can be regarded as the upgrade version GBIC. Unlike GBIC with SC fiber optic interfaces, cisco SFP is with LC interface. Moreover, its main body size of SFP is only about half of GBIC, which makes SFP space saving  It allows for seamless integration of fiber with copper LAN connections wherever SFP 1.25Gb/s interface slots are available. Such device is economical, it saves time, offers flexibility and eliminates the necessity for replacing entire devices when the customers need to change or upgrade fiber connections and you will benefit a lot from it.