Cisco OC-3/STM-1 1310-nm Wavelength Short-reach 2KM MMF Original Transceiver Module.Cisco Transceiver Module- SFP – 1310 nm – OC-3/ STM-1 SFP-OC3-MM Standard Interface Converter (SFP) for packet-over-SONET/SDH optical networking ATM applications are hot-swappable optical interfaces that plug into a variety of ports on Cisco router interfaces.