ATOP 100G ZR4 QSFP28 is designed for use in 100 Gigabit Ethernet, Telecom networking and Data Center Interconnect supporting a link distance up to 80Km on standard single-mode fiber (SMF). 100G Gigabit Ethernet signal is carried over four wavelengths. Multiplexing and demultiplexing of the four wavelengths are managed within the device.