400G-SR8 QSFP56-DD based on VCSEL, 8 channels of 50G-PAM4 electrical and optical parallel lanes,single optical port of MPO-16, up to 70m reach via OM3 multimode fiber and 100m reach reach via OM4 multimode fiber,case temperature range of 0℃-70℃, comply with IEEE 802.3bs and QSFP-DD MSA. Products are mainly used in 400G Ethernet, data centers and cloud networks.