This document provides specifications for the DWDM-SFP10G-40-C58-T02 10G 1531.12nm 40km DWDM SFP+ transceiver. It includes details on its product description, features, functional diagram, optical and electrical characteristics, pin definitions, digital diagnostic monitoring interface, package dimensions and ordering information. The transceiver is designed for 10 Gigabit Ethernet links up to 40km over single-mode fiber and supports DWDM channels with 100GHz spacing and a center wavelength of 1531.12nm. It provides digital diagnostics monitoring of parameters such as temperature, voltages, optical powers and bias currents.