The JBX05427 40GBASE-CR4 QSFP+ passive direct attach copper cable represents an optimal solution for modern data center infrastructure requiring high-speed, low-latency connectivity. Specifically designed for Ruckus network equipment compatibility, this 2.5-meter cable delivers exceptional performance for server-to-switch, switch-to-switch, and storage-to-network interconnections. **Technical Specifications:** This cable utilizes premium 30AWG twinax copper conductors wrapped in durable plastic jacketing, providing excellent electromagnetic shielding and signal integrity. The QSFP+ (Quad Small Form Factor Pluggable) connectors support full 40 Gigabit Ethernet transmission rates, making it ideal for bandwidth-intensive applications. Compliance with IEEE 802.3ba standards ensures interoperability and reliability across enterprise networks. **Key Features & Benefits:** Passive direct attach technology eliminates external power requirements, reducing operational costs and complexity. The compact 2.5-meter length provides flexibility for typical data center rack configurations and switch interconnections. RoHS and ELV compliant construction meets international environmental standards. Safety certifications from TUV and UL validate manufacturing quality and reliability. Custom brand programming options allow for corporate standardization and asset tracking. **Applications & Use Cases:** Ideal for enterprise data centers, high-performance computing clusters, cloud infrastructure, and virtualized environments requiring sub-3-microsecond latency. Compatible with Ruckus switches and networking equipment (replaces OEM part numbers E40G-QSFP-C-0251 and E40G-QSFP-QSFP-P-0251). **Operational Specifications:** Operates reliably in temperature ranges from 0°C to 70°C (32°F to 158°F). Ships from strategically located U.S. facilities in California and South Carolina for rapid delivery. Backed by a comprehensive 90-day limited warranty. **Why Choose This Cable:** Compared to active optical cables (AOC), passive DACs offer superior cost-efficiency, lower power consumption, and reduced heat dissipation—critical factors in densely populated data centers. The proven copper twinax design delivers decades of industry-standard performance. Free standard shipping on orders exceeding $99 makes this an economical infrastructure investment.