Youopto 400G Series is a 400Gbps transmitter optical subassembly(TOSA) integrating a high speed 4 LWDM EML chips ,a TFF LWDM Mux,a TEC and thermistor in a BOX package. It is   designed for use in small from-factor pluggable transceivers and other types of optical modules for   high-speed telecommunication and data applications。