Carry 40 GbE farther without changing the architecture. The StarTech QSFP40GLR4S compatible QSFP+ module is designed for 40GBASE-LR4 deployments over single-mode fiber, making it a practical choice for campus backbones, data center interconnects, and long-reach switch uplinks. For infrastructure teams, LR4 optics solve a specific problem: moving high-speed traffic across longer distances while preserving the port density of QSFP+ hardware. This compatible module gives you that capability in a form that fits supported Cisco QSFP-40G-LR4-S environments, helping standardize optics across mixed-vendor or cost-sensitive deployments. At 40 Gb/s, it supports the throughput expected in aggregation and backbone layers where oversubscription is not an option. Choosing a compatible module can also help control lifecycle costs when compared with OEM-branded optics, especially in fleets that require repeatable sourcing across many sites. The result is a clean fit for teams that need long-reach 40 GbE transport with disciplined procurement and no unnecessary platform changes.