The JBX02199 1000BASE-BX40-U SFP transceiver module is engineered for professionals who demand extended-reach optical connectivity without compromising on reliability or performance. This premium-grade transceiver operates seamlessly over 40 kilometers of singlemode fiber, utilizing 1310/1550nm wavelengths for bidirectional data transmission beyond standard IEEE 802.3ah specifications. **Technical Specifications:** This module features a 9/125 singlemode fiber core with simplex LC/UPC connectors, delivering 1Gbps data rates across extended distances. The compact form factor (5x4x2 dimensions) integrates seamlessly into standard SFP slots, while the metal case with precision-engineered laser transmitter ensures optimal signal integrity and minimal attenuation. **Compatibility & Performance:** Direct replacement for Arista SFP-1G-BXU40-35 OEM parts, ensuring plug-and-play installation in Arista-based network infrastructure. The extended-reach BiDi technology surpasses conventional SFP capabilities, enabling cost-effective long-distance deployments without requiring separate fiber pairs. **Quality & Compliance:** Manufactured to rigorous international standards, this transceiver carries RoHS/ELV compliance and EU directive 2002/95/EC certification. Safety features include Class 1 Laser designation, TUV and UL/FDA approvals per 21CFR 1040.10, ensuring safe operation in enterprise environments. **Operational Reliability:** Designed for demanding environments with operating temperatures ranging from 0 to 70°C (32 to 158°F). The 90-day limited warranty and custom brand programming options provide flexibility for various deployment scenarios. Free standard shipping on orders over $99 makes this professional-grade component accessible for network administrators and IT professionals. **Ideal Applications:** Perfect for metro networks, campus interconnects, disaster recovery links, and remote site connectivity where extended-reach fiber solutions are required without the complexity of dispersion compensation systems.