The JBX42487 5m ST/APC to ST/UPC Duplex Singlemode Fiber Patch Cable represents professional-grade fiber optic connectivity engineered for critical network infrastructure. This cable bridges ST/APC and ST/UPC connectors—a standard configuration in telecommunications and data center environments where cross-connector compatibility is required. **Technical Specifications:** The cable features a 9/125 singlemode fiber core with G.657.A1 glass composition, specifically designed for both short and long-distance signal transmission. Performance metrics include insertion loss of ≤0.35dB (0.15dB typical) and return loss ≥20dB, meeting rigorous telecommunications standards. Attenuation testing confirms performance at 1310 nm (0.25 dB/km) and 1550 nm (0.35 dB/km) wavelengths. **Construction and Durability:** The cable features a robust 1.8mm outside diameter with OFNR (Optical Fiber Non-conducting Riser) yellow jacket, providing fire safety compliance and visibility in network installations. Duplex configuration accommodates bidirectional signal transmission with Type A to B crossover polarity—the most common configuration for patch cord applications. **Compliance and Standards:** Fully TAA compliant and RoHS/ELV certified, this cable meets government procurement requirements. Manufacturing adheres to ANSI/TIA/EIA telecommunications standards with quality assurance across multiple production facilities (Taiwan, US, China). **Applications:** Ideal for data centers, telecommunications networks, enterprise infrastructure, and any application requiring reliable singlemode fiber connectivity. The 5-meter length provides optimal flexibility for structured cabling while the duplex configuration supports full-duplex communication. **Value and Warranty:** Enjoy free standard shipping on orders exceeding $99, with a 90-day limited warranty protecting your investment. Custom lengths available upon request for specialized installations.