ATOP SFP+ CWDM for SDH/PHD 40KM transceiver is designed for use in 10Gigbit, multi-rate links up to 40KM of G.652 single mode fiber. Compatible with SFF-8431, SFF-8432 and supporting SONET OC-192 /SDH STM-64 and 10G Ethernet ER protocol, this product is well suited for transmission networking and data centre interconnect applications. Digital diagnostics functions are available via an I2C interface, as specified by SFF-8472.