GIGALIGHT 200G QSFP-DD SR4 optical transceiver modules are used for short-range interconnections between devices within data centers and are compliant with 200G Ethernet transport protocols, as well as compatible with 4×50G Ethernet transport protocols. This module can convert 8 channels of 25Gbps (NRZ) electrical input data to 4 channels of 50Gbps (PAM4) optical signal, and also can convert 4 channels of 50Gbps (PAM4) optical signal to 8 channels of 25Gbps (NRZ) electrical output data. Maximum link length of 70m on OM3 Multimode Fiber (MMF) and 100m on OM4 MMF with KP-FEC.