The JBX42199 40-meter LC/APC to FC/UPC Duplex Singlemode Fiber Patch Cable represents a professional-grade solution for mission-critical network connectivity. Designed to meet stringent telecommunications standards, this optical cable delivers reliable, low-loss signal transmission for enterprise and carrier-class applications. **Technical Excellence:** This singlemode fiber patch cable utilizes a precision 9/125 micrometer core with G.657.A1 glass fiber specification, engineered to minimize attenuation and maximize signal fidelity. Measured insertion loss of ≤0.35dB (typical 0.15dB) ensures minimal signal degradation, while the return loss specification of ≥20dB prevents signal reflections that could compromise data integrity. Performance is verified in accordance with ANSI/TIA/EIA-455-171-A standards, guaranteeing consistency and reliability. **Connector Configuration:** Featuring LC/APC (Angled Physical Contact) connectors on one end and FC/UPC (Straight Physical Contact) on the other, this cable accommodates mixed-connector network architectures. The duplex Type A to B crossover polarity is standard for patch cord applications, enabling seamless integration with existing infrastructure. The 1.8mm outer diameter ensures compatibility with standard cable management systems. **Compliance & Safety:** Fully TAA compliant, this cable meets government procurement requirements. RoHS and ELV directive compliance ensures environmental responsibility. The OFNR (Optical Fiber Non-conductive Riser) rated yellow jacket provides fire safety in vertical installations while offering superior visibility for identification and management. **Practical Advantages:** The 40-meter length eliminates the need for intermediate splices, reducing insertion loss and maintaining signal integrity. The distinctive yellow jacketing simplifies cable identification in complex installations. Custom lengths are available for specialized applications. Backed by a 90-day limited warranty, this cable provides peace of mind for critical network deployments. **Applications:** Ideal for data center interconnects, telecommunications networks, long-distance signal transmission, and professional audio/video installations. The singlemode specification supports both legacy and next-generation network speeds, making it a versatile choice for evolving infrastructure.