This document specifies the technical details of a 1G 1410nm 40km CWDM SFP transceiver module. The module uses a CWDM DFB laser transmitter operating at a wavelength of 1410nm and supports data transmission up to 1.25Gbps over a distance of 40km in single mode fiber. It complies with small form-factor pluggable (SFP) and enhanced small form-factor pluggable (SFP+) industry standards. Key features and specifications such as optical power levels, wavelength ranges, data rates, temperature ranges, and pin definitions are provided.