The ATOP 100G QSFP28 LR4 transceiver supports a link distance of 10 km on standard single-mode fiber and is used together with LC single-mode fiber jumpers. It adopts a design of 4 LAN-WDM lanes for MUX/DEMUX and hot-pluggable QSFP28 packaging, which has 4 independent full-duplex channels that can transmit up to 25Gbps data rate per wavelength. This module has a power dissipation of < 4.5W and can be operated from 0°C to 70°C. This 100G-LR4 QSFP 28 module can be applied to 100GBASE-LR4 and 100G Ethernet applications.