Cisco GLC-EX-SMD= 1000Mbit/s SFP 1310nm Single-mode network transceiver module

Cisco 1000Base-EX SFP Module - 1 x 1000Base-EX 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.