The JBX42500 ST/APC to ST/UPC duplex singlemode fiber patch cable represents a superior solution for modern telecommunications and data center infrastructure. Spanning 45 meters, this cable delivers the performance and reliability required for mission-critical applications. **Key Technical Specifications:** This duplex cable features a 9/125 singlemode core constructed with G.657.A1 glass fiber, the industry standard for long-distance signal transmission. The ST/APC connector on one end (angle-polished for 20dB+ return loss) connects to an ST/UPC connector on the other, creating a Type A to B crossover configuration—the most common polarity for duplex patch cord installations. Insertion loss is rated at ≤0.35dB (0.15dB typical), ensuring minimal signal degradation. Attenuation specifications meet rigorous ANSI/TIA/EIA-455-171-A standards, with 0.25 dB/km @ 1310nm and 0.35 dB/km @ 1550nm performance. **Construction & Safety:** The cable features a 1.8mm outside diameter with durable plastic accessory components and riser-rated (OFNR) jacketing. The distinctive yellow jacket provides instant visibility in crowded cable environments, simplifying maintenance and troubleshooting. RoHS and ELV compliant, this cable meets EU directive 2002/95/EC standards. **Compliance & Certification:** TAA-compliant for federal government procurement, this cable satisfies Buy American requirements. Manufactured with precision in Taiwan, the United States, and China, it maintains consistent quality across production batches. **Flexibility & Support:** Available in custom lengths beyond the standard 45m offering, this cable adapts to specific installation requirements. It ships with free standard shipping on orders exceeding $99 from multiple distribution centers (Danville CA, Fort Worth TX, Beaufort SC), ensuring rapid delivery. The 90-day limited warranty provides peace of mind for your investment. **Applications:** Ideal for telecom networks, data centers, LAN environments, and any installation requiring duplex singlemode connectivity with Type A/B polarity configuration.