Keep long-reach 40 GbE connections stable with a QSFP+ transceiver designed for Arista-compatible deployments. The AddOn QSFP-40G-LR4-AR-AO delivers 40GBase-LR4 performance over single-mode fiber, making it a practical fit for data center interconnects, aggregation links, and backbone runs that need predictable optical behavior. This module is built for teams that want standards-based optics without the uncertainty of generic replacements. It supports up to 10 km of reach, uses an LC connector, and is programmed, serialized, and tested for compatibility in environments where link initialization and steady traffic handling are essential. For infrastructure groups managing spares, refreshes, or multi-vendor estates, that reduces qualification effort and helps protect uptime. TAA compliance adds procurement flexibility for regulated purchasing, while the hot-swappable QSFP+ design supports fast replacement during maintenance windows. When the cost of a failed optic includes troubleshooting time, service disruption, and delayed deployment, a verified transceiver like this earns its place.