The JBX42525 ST/APC to ST/APC duplex singlemode fiber patch cable represents a premium solution for critical network infrastructure applications. Manufactured to exacting specifications, this 20-meter cable delivers exceptional optical performance suitable for demanding telecommunications environments. **Technical Specifications:** This cable features a 9/125 singlemode fiber core with G.657.A1 glass fiber composition, engineered for superior signal integrity. Attenuation performance is rated at 1310 nm: 0.25 dB/km or 1550 nm: 0.35 dB/km, with typical insertion loss of just 0.15dB—well below the ≤0.35dB maximum specification. Return loss of ≥20dB ensures minimal signal reflection. The cable undergoes attenuation testing in accordance with ANSI/TIA/EIA-455-171-A-2001 standards. **Key Features:** The yellow OFNR (Optical Fiber Nonconductive Riser) rated jacket provides flame-resistant protection with a 1.8mm outer diameter for efficient cable routing. Type A to B crossover polarity configuration is optimized for standard duplex patch cord deployments. TAA compliance and RoHS/ELV certification meet regulatory requirements for government and enterprise procurement. **Applications:** Ideal for data centers, telecommunications facilities, broadcast facilities, and long-distance network connections requiring singlemode performance. The duplex configuration enables simultaneous bidirectional transmission, essential for full-duplex communication systems. **Customization & Logistics:** While this product is available in a 20m standard length, custom lengths are available upon request. Free standard shipping applies to orders exceeding $99, with shipment from multiple distribution centers (Danville, CA; Fort Worth, TX; Beaufort, SC) ensuring rapid delivery. The cable includes a 90-day limited warranty. **Professional Installation:** For optimal performance, ensure proper handling during installation. Avoid excessive bending radius and maintain connector cleanliness to preserve insertion loss specifications. ST/APC connectors feature angled polish design, reducing reflectance for superior signal quality.