The JBX42726 ST/APC to LC/UPC duplex singlemode fiber patch cable represents professional-grade connectivity for critical network infrastructure. This 4-meter cable assembly combines precision engineering with reliable performance to ensure optimal signal transmission in demanding telecommunications environments. **Technical Excellence:** Constructed with 9/125 singlemode fiber core meeting G.657.A1 specifications, this cable supports both traditional and next-generation network protocols. The ST/APC connectors feature angled physical contact for superior return loss (≥20dB), while LC/UPC connectors provide universal compatibility. Type A to B crossover polarity configuration is optimized for duplex transmission, making this cable suitable for most standard network applications. **Performance Specifications:** Tested in accordance with ANSI/TIA/EIA-455-171-A-2001 standards, this cable delivers exceptional low-loss performance with ≤0.35dB insertion loss and typical attenuation of 0.15dB. At 1310 nm, attenuation measures 0.25 dB/km; at 1550 nm, 0.35 dB/km—ideal for both legacy systems and DWDM applications. The 1.8mm outside diameter provides flexible routing through cable trays and conduit while maintaining structural integrity. **Build Quality & Compliance:** The OFNR-rated yellow jacket provides fire protection and easy cable identification in crowded installation environments. RoHS/ELV compliant manufacturing ensures environmental responsibility. TAA compliance enables use in government and federal projects. Custom length availability accommodates specific installation requirements. **Applications:** Ideal for data center interconnects, telecommunications facilities, laboratory equipment, and access network installations where reliable, low-loss fiber transmission is critical. The duplex configuration supports simultaneous bidirectional communication, reducing the need for multiple cable runs. **Value & Support:** Ship from multiple U.S. locations (Danville CA, Fort Worth TX, Beaufort SC) ensures rapid delivery. Free standard shipping applies on orders exceeding $99. Professional-grade construction backed by 90-day limited warranty provides confidence in long-term performance reliability.