The JBX01958 is a high-performance 100BASE-BX20 SFP optical transceiver designed for telecommunications professionals and network infrastructure operators. This module represents an ideal balance between performance, reliability, and cost-effectiveness for extended-reach network applications. **Key Technical Specifications:** Operating at 100Mbps over single-mode fiber, this transceiver delivers 20-kilometer transmission distances—ideal for connecting remote facilities, campuses, or metropolitan areas. The 9/125 micrometer core single-mode fiber ensures minimal signal loss and exceptional data integrity. The simplex LC/UPC connector provides industry-standard, low-insertion-loss connectivity with consistent performance. **Compatibility & Integration:** This module directly replaces Cisco's GLC-FE-100BX-U-RGD transceiver, ensuring plug-and-play compatibility with existing Cisco networking equipment. No additional configuration or firmware updates are required, making installation straightforward for IT teams. **Safety & Compliance:** Manufactured to the highest standards, the JBX01958 carries Class 1 laser safety certification (LN #50 7/2001) and meets TUV, UL, and FDA requirements per 21CFR 1040.10. Full RoHS and ELV compliance ensures environmental responsibility and regulatory adherence across global markets. Qualification to SFF-8472 extended-reach BiDi specifications guarantees performance beyond standard IEEE 802.3ah requirements. **Robust Design:** The metal case construction with integrated laser transmitter provides excellent thermal management and EMI shielding. Operating reliably from -40°C to +85°C, it performs consistently in demanding environments including outdoor installations, HVAC-limited closets, and industrial settings. **Value Proposition:** With free standard shipping on orders exceeding $99 and a 90-day limited warranty, this transceiver offers exceptional value. Custom brand programming is available for enterprise deployments requiring standardized asset identification. Ships from convenient U.S. locations (Danville, CA and Beaufort, SC) for rapid delivery. **Ideal Applications:** Network managers upgrading legacy infrastructure, engineers designing metro-area networks, and IT professionals requiring reliable, cost-effective extended-reach connectivity will find this module indispensable. Perfect for point-to-point links, redundant paths, and long-haul metropolitan area network (MAN) implementations.