The JBX42553 ST/APC to FC/UPC Duplex Singlemode Fiber Patch Cable represents enterprise-class connectivity for mission-critical fiber optic networks. This 12-meter duplex configuration delivers reliable, high-speed data transmission across telecommunications, data center, and network infrastructure installations. **Technical Excellence:** Built with 9/125 singlemode fiber architecture, this cable optimizes performance at both 1310nm and 1550nm wavelengths—the standard operating frequencies for long-distance telecommunications. Attenuation specifications of 0.25dB/km at 1310nm and 0.35dB/km at 1550nm demonstrate minimal signal loss over extended distances. The insertion loss rating of ≤0.35dB ensures clean signal transmission with <0.15dB typical performance, while ≥20dB return loss prevents signal reflections that could compromise network integrity. **Professional Design:** The duplex configuration enables simultaneous bidirectional communication through two independent fiber strands, essential for full-duplex telecommunications systems. ST/APC connectors provide angled physical contact for superior return loss characteristics, while FC/UPC terminations offer universal compatibility. The Type A to B crossover polarity configuration is optimized for duplex patch cord applications. **Standards Compliance:** RoHS/ELV and TAA compliant construction ensures regulatory adherence for government and enterprise procurement. Attenuation testing follows ANSI/TIA/EIA-455-171-A-2001 standards, guaranteeing measured performance. The G.657.A1 fiber rating supports modern bend-insensitive installations without performance penalties. **Installation & Protection:** The 1.8mm diameter yellow OFNR jacket provides visible identification while maintaining riser-rated fire safety classification. Suitable for both horizontal and vertical installations in telecommunications closets, data centers, and network backbone systems. 90-day limited warranty included. Available in custom lengths for specific deployment requirements. **Applications:** Ideal for telecommunications signal transmission, WAN connectivity, data center interconnects, fiber backbone networks, and high-speed data communications requiring duplex full-duplex capability. Ships from multiple U.S. locations with free standard shipping on orders exceeding $99.