The TP-Link ISM321A-20 is a high-performance 1000Base-BX WDM bi-directional industrial SFP module designed for single-mode fibre networks. Utilizing Wavelength Division Multiplexing (WDM) technology, this module enables data transmission and reception over a *single strand of fibre* (simplex), significantly reducing installation and operational costs related to fibre infrastructure.

This compact and hot-pluggable SFP transceiver with an LC connector is compatible with the Small Form-factor Pluggable Multi-Source Agreement (SFP-MSA), ensuring seamless interoperability with a broad range of network devices. The ISM321A-20 supports Digital Diagnostic Monitoring (DDM), allowing real-time access to vital parameters such as optical input/output power, temperature, laser bias current, and supply voltage for enhanced network reliability and maintenance.

Engineered for industrial applications, it withstands extreme environmental conditions with an extended operating temperature range from -40°C to 85°C, making it ideal for deployment in harsh or outdoor environments.

Backed by a 3-year warranty, the TP-Link ISM321A-20 provides reliable, cost-effective fiber connectivity for demanding industrial and enterprise network infrastructures.