The JBX42019 40-meter LC/APC to LC/UPC duplex single mode fiber patch cable represents a reliable solution for modern network infrastructure requiring high-speed, long-distance data transmission. This professionally-manufactured cable combines precision engineering with adherence to international standards. **Technical Excellence:** Built on 9/125 single mode fiber core with G.657.A1 specification, the cable achieves outstanding performance metrics: insertion loss of ≤0.35dB (0.15dB typical), return loss ≥20dB at 1310nm and 1550nm wavelengths, and attenuation rates of 0.25 dB/km at 1310nm or 0.35 dB/km at 1550nm. All measurements comply with ANSI/TIA/EIA-455-171-A-2001 standards, ensuring predictable performance in your network environment. **Connector Compatibility:** The LC/APC to LC/UPC configuration provides Type A to B crossover polarity, the most common setup for duplex patch cord applications. This ensures seamless integration with existing telecommunications infrastructure and data center equipment. **Durability & Compliance:** The 1.8mm outside diameter jacket features OFNR (Riser Rated) construction, meeting safety requirements for in-building vertical runs. TAA (Trade Agreements Act) compliance and RoHS/ELV certification make this cable suitable for government and regulated industry procurement. The yellow jacket enhances visibility during installation and maintenance, reducing cable mix-ups in complex installations. **Practical Advantages:** With custom lengths available, you can order exactly what your project requires without waste. Quick delivery from strategically located US warehouses in California, Texas, and South Carolina ensures minimal lead times. The 90-day limited warranty provides peace of mind. **Applications:** Ideal for telecommunications closets, data centers, ISP networks, and enterprise backbone connections where single mode performance is essential. Perfect for long-distance transmission, campus networking, and high-bandwidth requirements. Compatible with standard LC connector equipment from major manufacturers. **Value Proposition:** This cable delivers professional-grade performance at competitive pricing with free shipping on qualifying orders, making it an economical choice for both small upgrades and large-scale deployments.