The far end of your 20 km fibre run needs a converter that actually talks to the MC211CS-20 you've already got. The MC212CS-20 is that half. One RJ45 port, auto-negotiating up to gigabit, WDM on a single fibre strand. You pair it up, connect your device, and the link is live. No SFP hunting. No six-week backorder from a marketplace that
| brand | TP-Link |
| model | MC212CS-20 |
| category | Networking |
| subcategory | Media Converters |
| port_type | RJ45 |
| port_speed | 10/100/1000 Mbps |
| auto_negotiation | 1 |
| auto_mdi_mdix | 1 |
| duplex_mode | Half-Duplex / Full-Duplex (auto) |
| wavelength_technology | WDM |
| fibre_type | Single-mode |
| max_fibre_distance_km | 20 |
| fibre_strands_required | 1 |
| pairing_model | MC211CS-20 |
| warranty_years | 3 |
