The JBX02158 1000BASE-BX20 SFP transceiver module is a professional-grade optical component designed for enterprise and carrier-class networking environments requiring extended-reach connectivity. This device provides 20-kilometer transmission capability over standard 9/125 single-mode fiber, making it ideal for campus networks, metropolitan area networks (MANs), and long-distance data center interconnects. **Key Technical Specifications:** Operating at 1Gbps data rates, this SFP module utilizes opposing 1310nm and 1490nm wavelengths for simultaneous bidirectional communication over a single fiber strand. The simplex LC/UPC connector configuration ensures compatibility with standard network infrastructure while maintaining excellent optical coupling efficiency and minimal back-reflection loss. **Compatibility and Integration:** Fully compatible with Cisco GLC-BX-U20 systems and qualified to SFF-8472 specifications, this transceiver integrates seamlessly into existing Cisco network deployments. It directly replaces OEM part numbers GLC-BX-U20 and MA-SFP-1GB-BX20-U without requiring firmware updates or configuration changes. **Compliance and Certifications:** Manufactured to the highest quality standards, the JBX02158 carries multiple safety and environmental certifications including Class 1 Laser designation, TUV, UL/FDA compliance, and RoHS/ELV directives. The metal case construction provides electromagnetic shielding while protecting sensitive laser components. **Reliability and Support:** Operating across the extended temperature range of 0-70°C (32-158°F), this transceiver performs consistently in diverse environmental conditions. Each unit includes a 90-day limited warranty and benefits from custom brand programming availability for OEM applications. Ships from US locations with free standard shipping on qualifying orders. **Applications:** Ideal for network operators, system integrators, and data center managers seeking cost-effective extended-reach connectivity without compromising performance or reliability.