The JBX05179 0.5m Arista CAB-Q-S-0.5M compatible 40GBASE-CR4 QSFP+ to 4x SFP+ direct attach copper (DAC) breakout cable represents premium networking infrastructure designed for demanding data center environments. This passive breakout solution eliminates the need for active transceiver modules, reducing power consumption and operational costs while maintaining optimal performance. **Technical Specifications:** This cable features 30AWG twinax copper conductors engineered to deliver 40Gbps throughput per the IEEE 802.3ba standard. The 0.5-meter length accommodates short-reach interconnections common in top-of-rack and end-of-row switching configurations. The QSFP+ connector interfaces with a single high-speed port, while the opposite end provides four discrete SFP+ connectors for granular port distribution. **Compliance & Certifications:** Fully compliant with EU RoHS Directive 2002/95/EC and qualified to the latest IEEE 802.3ba specifications. Certified by TUV and UL for safety and reliability. The copper construction with plastic jacketing ensures electromagnetic shielding while maintaining flexibility for installation in congested cable runs. **Applications:** Ideally suited for Arista switch migrations, network fabric upgrades, high-frequency trading platforms, cloud infrastructure expansions, and enterprise data center modernization projects. The breakout configuration allows operators to efficiently utilize high-capacity ports when connecting to legacy 10GbE infrastructure. **Performance & Reliability:** Operates across 0-70°C environmental conditions, supporting consistent data transmission in temperature-controlled data center facilities. The 90-day limited warranty provides assurance of product quality. Ships from strategically located US warehouses (Danville, CA and Beaufort, SC) ensuring rapid delivery. **Cost Advantages:** As a passive DAC solution, this cable requires no power, generating minimal heat compared to active alternatives. Eliminates recurring transceiver licensing costs while delivering carrier-grade performance suitable for mission-critical network operations. The direct attachment design minimizes latency and provides deterministic connectivity.