https://www.gearlinkoptic.com/products/sfp-1.25g-1550nm-80km-lc-transceiver/
GearLink's gigabit optical transceiver GCS7L0C55 is used in Gigabit Ethernet, dual-channel, and bidirectional transmission synchronous optical network (SONET). It conforms to SFP multi-source protocol and SFF-8472, with digital diagnostic monitoring(DDM) function. The package of GCS7L0C55 is SFP with LC interface, the rate is 1.25G, the optical wavelength is 1550NM, and the maximum transmission distance is 80KM.
Compatibility of SFP 1.25G 1550nm 80Km LC Transceiver
GLC-ZX-SM-RGD 1000BASE-ZX SFP 1550nm 70km
SFP-GE-Z 1000BASE-ZX SFP 1550nm 70km
GLC-ZX-SM 1000BASE-ZX SFP 1550nm 70km
GLC-ZX-SM 1000BASE-ZX SFP 1550nm 70km
GLC-ZX-SMD
WS-G5487 1000BASE-ZX SMF 1550nm 70km GBIC
WS-G5486 1000BASE-ZX SFP 1550nm 70km