The JBX02156 1000BASE-BX20 SFP transceiver is a sophisticated optical networking component engineered for mission-critical telecommunications and data center applications requiring extended transmission distances. This advanced module delivers 1 gigabit per second (1Gbps) data rates over single-mode fiber (SMF) spans of up to 20 kilometers, making it ideal for metropolitan area networks (MANs) and wide area network (WAN) deployments. **Key Technical Specifications:** Operating at 1310nm transmit and 1490nm receive wavelengths, this bidirectional (BiDi) transceiver utilizes wavelength division multiplexing (WDM) to achieve full-duplex communication over a single fiber strand. The 9/125 micron singlemode fiber core ensures excellent signal integrity and minimal attenuation over extended distances. The simplex LC/UPC connector provides industry-standard connectivity with low-loss optical interfaces. **Compatibility and Integration:** Fully compatible with Arista SFP-1G-BXU20 specifications, this module integrates seamlessly into existing Arista network environments without requiring configuration changes. Custom brand programming is available for OEM applications and network standardization requirements. **Quality and Reliability:** Manufactured to stringent industry standards, the transceiver features a robust metal case with integrated laser transmission technology. It holds multiple safety certifications including Class 1 Laser (TUV, UL/FDA per 21CFR 1040.10) and complies fully with RoHS/ELV and EU directive 2002/95/EC regulations. Qualified to SFF-8472 extended-reach specifications, it exceeds standard IEEE 802.3ah requirements. **Performance Characteristics:** The module maintains optimal performance across a wide operating temperature range of 0-70°C (32-158°F), making it suitable for diverse deployment environments. Compact dimensions (5.0" × 4.0" × 2.0") enable easy installation in standard SFP slots without additional modification. **Value and Support:** Backed by a 90-day limited warranty and offering free standard shipping on orders exceeding $99, this transceiver represents an economical solution for network expansion and equipment replacement. Ships from multiple U.S. locations (Danville, CA and Beaufort, SC) for faster delivery. **Ideal Applications:** Perfect for telecommunications providers, ISPs, enterprise data centers, campus network extensions, and service provider backhaul networks requiring cost-effective extended-reach connectivity. Particularly valuable for organizations seeking Arista-compatible alternatives with proven reliability and exceptional performance.