Bidi قصص

https://www.optical-sintai.com/products/sfp-bidi-transceiver.html Designed for Ethernet, Fiber Channel, SDH, SONET, or CPRI links over simplex single-mode fiber, the Sintai SFP BiDi optical transceiver use 1310nm, 1490nm, or 1550nm wavelengths and support transmission distance up to 120km and are used in pairs.

https://www.gearlinkoptic.com/products/sfp-1.25g-tx1550-rx1490-80km-lc-transceiver/ Gearlink's GCS7L0C54 SFP transceiver is compatible with the Small Form Factor Pluggable Multi-Sourcing Agreement (MSA). The china optical transceiver consists of five sections: the LD driver, the limiting amplifier, the digital diagnostic monitor, the 1490nm DFB laser (the 1550nm DFB laser), and the PIN/TIA. The module data link up to 80km in 9/125um Single-mode fiber.