The JBX02145 1000BASE-BX120 SFP transceiver is a professional-grade optical module engineered for extended-reach network applications requiring reliable 1Gbps transmission over distances up to 120 kilometers. This module represents a cost-effective alternative to OEM-branded solutions while delivering identical performance and reliability. **Key Technical Features:** Operating at 1490/1550nm wavelengths, this bidirectional transceiver supports simplex transmission over 9/125 single-mode fiber with LC/UPC connectors. It qualifies to SFF-8472 specifications and extends beyond standard IEEE 802.3ah specifications, ensuring compatibility with advanced networking environments. The metal case construction houses a precision laser transmitter, providing durability in demanding deployment scenarios. **Performance & Compatibility:** Designed as a direct replacement for Arista SFP-1G-BXU120 modules, this transceiver integrates seamlessly into existing network infrastructure without requiring firmware updates or reconfiguration. The 120km reach eliminates the distance limitations of standard 10km SFP modules, making it ideal for campus networks, metropolitan area networks, and disaster recovery configurations. **Safety & Compliance:** Comprehensive certifications include Class 1 Laser designation, TUV approval, UL/FDA compliance (21CFR 1040.10), and full RoHS/ELV directive adherence (EU 2002/95/EC). These certifications ensure safe operation in regulated environments and simplify procurement for enterprise deployments. **Operational Specifications:** The module operates reliably across 0-70°C temperature ranges, supporting both hot and cold climate deployments. Its compact 5x4x2mm form factor fits standard SFP slots without adapter plates or special mounting hardware. **Warranty & Support:** Backed by a 90-day limited warranty and custom brand programming availability for enterprise customers. Ships from strategic US locations (Danville, CA and Beaufort, SC) with free standard shipping on orders exceeding $99, making it an accessible solution for network upgrades and expansion projects.