GLC-EX-SMD= - Fiber optic - 1000 Mbit/s - SFP - 40000 m - 1310 nm - Cisco ME 3400 - Cisco Catalyst 3750

The Cisco 1000BASE-EX SFP operates on standard single-mode fiber-optic link spans of up to 40 km in length. A 5-dB inline optical attenuator should be inserted between the fiber-optic cable and the receiving port on the SFP at each end of the link for back-to-back connectivity.