JFOPT QSFP56-200G-LR4 optical transceiver is developed and produced based on the standards Ethernet IEEE 802.3cd and QSFP56 MSA. It, adopted LAN-WDM EML TOSA and PIN ROSA, is a four channels full duplex transceiver, each lane data rate up to 50Gbps(PAM4), and the highest data rate of the transceiver up to 212.5Gbps.