The JBX42561 ST/APC to FC/UPC duplex singlemode fiber patch cable represents professional-grade connectivity solutions for demanding network infrastructure. At 50 meters in length, this cable provides the extended reach necessary for campus and data center installations without signal degradation. **Technical Excellence:** Built with 9/125 singlemode fiber and G.657.A1 glass specifications, this cable meets ANSI/TIA/EIA standards for attenuation testing. It delivers exceptional performance with insertion loss as low as 0.15dB typical and guaranteed maximum of 0.35dB, and return loss exceeding 20dB. The cable maintains consistent performance across both 1310nm and 1550nm wavelengths, with attenuation rated at 0.25 dB/km and 0.35 dB/km respectively—ideal for both legacy and modern optical systems. **Connector Configuration:** The ST/APC to FC/UPC connector pairing accommodates Type A to B crossover polarity, the most common configuration for duplex patch cord applications. This proven connector combination provides reliable connections in telecommunications, CATV, and data transmission applications where precise signal delivery is essential. **Build Quality & Compliance:** The 1.8mm outside diameter allows for flexible routing through cable trays and conduit. The yellow OFNR-rated jacket provides both identification and fire safety compliance for building installations. RoHS/ELV and TAA compliance certifications make this cable suitable for government contracts and environmentally conscious operations. **Practical Advantages:** Offered with free standard shipping on orders exceeding $99 and shipped from multiple US locations (Danville CA, Fort Worth TX, Beaufort SC), this cable provides rapid deployment capabilities. Custom length options accommodate non-standard installation requirements. The 90-day limited warranty demonstrates manufacturer confidence in product reliability. **Applications:** Ideal for telecommunications infrastructure, data center interconnects, enterprise network backbones, CATV systems, and any application requiring singlemode fiber connectivity with extended reach and superior signal integrity. Whether upgrading legacy systems or building new installations, this cable delivers the performance and reliability modern networks demand.