Buy SFP Plus 10 gigabit (mini-GBIC) LC module single mode simplex TX: 1330nm RX: 1270nm 40km?
Does Multimode SFP Work Over Single-mode Fiber Cable? | by Monica Geller | Medium
Single Fiber 10 km SFP+ Optical Transceiver: BIDI-10G-SFP-10B
SFP-5040-WA - Fast Ethernet OC3 or STM-1 BiDirectional single strand WDM SFP transceiver, Tx:1310nm/Rx:1550nm, type A, max range 40Km, single LC connector
2A-137G - Fiber Single-Mode 1.25G SFP Transceiver Module up to 6.2mi/10KM (2 pcs)