The Cisco GLC-LH-SMD is a high-quality, 1000BASE-LX/LH Small Form-Factor Pluggable (SFP) transceiver module designed for robust Gigabit Ethernet applications. This versatile module supports a maximum data rate of 1.25 Gbps and can be deployed over both Single-Mode Fiber (SMF) and Multi-Mode Fiber (MMF). When connected to standard single-mode fiber, it achieves reliable links up to 10 kilometers (6.2 miles). For multi-mode fiber connections, it can reach up to 550 meters, though an industry-standard mode conditioning patch cable is required for optimal performance. The GLC-LH-SMD operates at a 1310 nm wavelength and uses a Duplex LC connector. A significant feature is its Digital Optical Monitoring (DOM) capability, indicated by the ‘SMD’ suffix. DOM allows network administrators to monitor real-time operational parameters such as transmitted and received optical power, temperature, and supply voltage, which is essential for proactive network maintenance and diagnostics. The module is hot-swappable, ensuring easy installation or replacement without needing to power down the host device, thereby maximizing network uptime. Compatible with the IEEE 802.3z 1000BASE-LX standard, the GLC-LH-SMD is an ideal choice for inter-building connections, campus backbone networks, and connecting high-performance switches and routers within an enterprise infrastructure. Its genuine Cisco design guarantees seamless compatibility and reliable long-term performance across a wide range of Cisco networking equipment.