The 400G QSFP-DD FR4 is a transceiver module designed for 2 km optical communication applications, and it is compliant with 100G Lambda MSA standard. This module can convert 8-channel 53.125 Gbps electrical data to 4-channel 106.25 Gbps optical signals, and multiplex them into a single channel for 425 Gbps optical transmission. Similarly, it optically de-multiplexes a 425 Gbps input into 4-channel signals, and converts them to 8-channel output electrical data on the receiver side.