The AddOn Cisco Compatible SFP-25G-ER-I is a high-performance 25-Gigabit SFP28 transceiver engineered for extended-reach data transmission over single-mode fiber. Operating at 1310nm wavelength, this module delivers reliable 25.78 Gbps throughput across distances up to 40 km (24.9 miles), making it ideal for metropolitan area networks, campus interconnects, and enterprise deployments requiring high-speed connectivity over substantial distances. The industrial temperature rating (-40°C to 85°C) ensures dependable operation in extreme environments where standard commercial optics would fail, including outdoor installations, manufacturing facilities, and harsh climate conditions. Featuring a duplex LC connector interface for secure single-mode fiber connectivity, this compact SFP28 transceiver supports 25GBASE-ER standards and is designed for demanding network infrastructure applications. As a TAA Compliant module, it meets stringent sourcing requirements for U.S. Federal Government, Department of Defense, and GSA-schedule procurement projects, ensuring full eligibility for government and military network deployments.