The JBX04991 3-meter 400GBASE-CR8 QSFP-DD to 2x QSFP56 direct attach copper cable represents a high-performance networking solution designed for modern data center environments. As a direct replacement for the Arista CAB-D-2Q-400G-3M, this passive breakout DAC cable enables efficient 400GB connectivity with minimal complexity. **Key Technical Specifications:** This cable features a robust 26AWG twinax copper construction with professional-grade plastic jacketing, engineered to deliver consistent 400GBASE-CR8 performance over its 3-meter length. The passive design eliminates the need for additional power sources, reducing operational complexity and cost. Operating temperature range of 0-70°C (32-158°F) ensures reliability across diverse data center environments. **Compliance & Standards:** Fully qualified to ETC 400GBASE-CR8 specifications and compliant with QSFP-DD MSA and CMIS standards. The cable meets RoHS (2002/95/EC), TUV, and UL certifications, ensuring environmental responsibility and safety in enterprise deployments. **Performance Benefits:** The QSFP-DD to dual QSFP56 breakout configuration allows flexible port expansion, enabling single 400GB connections to split into dual 200GB connections when needed. This versatility supports various network topology requirements without sacrificing signal integrity or introducing latency. The passive copper implementation provides superior performance compared to active cables for short-distance applications. **Applications & Use Cases:** Ideal for data center interconnects, high-performance computing clusters, and enterprise network infrastructure. Perfect for organizations deploying Arista switches and requiring cost-effective, low-latency connectivity solutions. Supports demanding applications including cloud computing, financial services, and large-scale virtualization environments. **Quality Assurance:** Backed by a 90-day limited warranty and shipped from strategically located U.S. fulfillment centers in Danville, CA and Beaufort, SC. Enjoy free standard shipping on orders exceeding $99, with custom brand programming available for enterprise customers requiring white-label solutions. Choose the JBX04991 for reliable, standards-compliant 400GB breakout connectivity that meets the demands of modern high-performance networking.