Mikrotik S-3553LC20D Network Transceiver Module

S-35/53LC20D is a pair of 1.25G single-mode optical SFP transceivers with LC connectors for up to 20 km links and support for DDM. The S-35LC20D transmits at 1310 nm and receives at 1550 nm, while the S-53LC20D transmits at 1550 nm and receives at 1310 nm. These modules are compatible with MikroTik devices such as RB260GS, RB2011LS, RB2011LS-IN, RB2011UAS-IN, RB2011UAS-RM, RB2011UAS-2HnD, RB2011UAS-2HnD-IN and CCR1036-12G-4S, and they also work with non-MikroTik SFP equipment.

Advantages

The modules provide a standardized SFP interface with a maximum data transfer rate of 1250 Mbit/s and LC fiber connectors for single-mode fiber links up to 20 km. Both transceivers support Digital Diagnostics Monitoring (DDM) for real-time status of optical parameters. The complementary wavelengths (1310/1550 nm) allow use in bi-directional fiber links over a single fiber strand.

Suitable for

• Long-distance single-mode fiber connections up to 20 km
• MikroTik routers and switches listed as compatible (RB260GS, RB2011 series, CCR1036-12G-4S)
• Interoperable links with non-MikroTik SFP devices
• BDM/monitoring setups requiring DDM support

Key specifications

• Form factor: SFP
• Data rate: 1.25 Gbit/s (1250 Mbit/s)
• Fiber type: Single-mode
• Connector: LC
• Wavelengths: S-35LC20D T1310 nm / R1550 nm; S-53LC20D T1550 nm / R1310 nm
• Maximum link distance: 20 km
• DDM: Supported
• Manufacturer MPN: S-3553LC20D

How to use

Insert each SFP transceiver into the SFP slot of the compatible switch or router until it clicks. Connect single-mode LC fiber cables to the LC ports, observing transmit/receive orientation for the bi-directional pair (S-35LC20D to S-53LC20D). Ensure the connected devices are powered and configured to use 1.25G SFP ports; the modules will negotiate the appropriate link automatically. Use the device management interface to verify link status and DDM readings if available.

Recommendations

Handle the optical interfaces carefully: keep dust caps on until installation, avoid bending the fiber below the minimum bend radius, and confirm compatibility with your equipment firmware. For bi-directional links, pair S-35LC20D and S-53LC20D on opposite ends of the same fiber to ensure correct wavelength routing.