The JBX01199 40GBASE-ER4 QSFP+ Transceiver represents a cutting-edge solution for enterprise-grade optical networking applications. Built to IEEE 802.3ba and SFF-8436 standards, this transceiver module delivers exceptional performance in demanding network environments requiring high-speed, long-distance connectivity. **Technical Excellence and Performance** Operating at 40Gbps, this transceiver achieves transmission distances up to 40 kilometers over standard single-mode fiber (9/125 core). The duplex LC/UPC connector design ensures excellent optical performance with minimal signal loss and low return loss, critical factors for network reliability. **Key Features** The module features a robust metal case housing an integrated laser transmitter system, optimized for sustained operation across commercial temperature ranges (0-70°C). The precision-engineered singlemode design with UPC connectors delivers superior signal integrity for carrier-class applications. Compact QSFP+ form factor enables high-density port configurations in modern data center and carrier infrastructure. **Compatibility and Integration** Fully compatible with Arista networking equipment, this transceiver serves as a direct replacement for OEM part QSFP-40G-ER4. Seamless integration into existing ecosystems minimizes deployment complexity and reduces total cost of ownership. **Compliance and Safety** Comprehensively certified with RoHS/ELV compliance, Class 1 Laser classification, and full FDA/UL certifications per 21CFR 1040.10. Manufactured to international standards (EU directive 2002/95/EC), ensuring global compatibility and regulatory adherence. **Value Proposition** With free standard shipping on orders exceeding $99, custom brand programming capabilities, and a 90-day limited warranty, this transceiver offers exceptional value. Ideal for network architects, data center operators, and telecommunications professionals requiring reliable, cost-effective 40G optical connectivity. **Applications** Perfect for metropolitan area network (MAN) expansion, data center interconnection (DCI), campus network backbone upgrades, and carrier network deployments. Whether expanding existing infrastructure or building new network systems, this transceiver delivers proven performance and reliability.