All Adtran® compatible SONET SFP transceiver modules are certified for functionality, reliability and performance under rigorous testing parameters. Every SONET SFP is RoHS and MSA compliant and built with Tier 1 grade components and lasers. Each Adtran® compatible SONET SFP module is individually tested in it's intended application with identical functionality to the OEM product. All ENET SONET SFP modules are backed by an industry-leading lifetime replacement warranty and technical support.