Carry high-bandwidth optical traffic over single-mode fiber with an 800 Gbps QSFP-DD transceiver using the 2xFR4 optical format. The module supports a stated reach of 2 km and uses two LC duplex optical connections. Its specified 1271–1331 nm wavelength range aligns with FR4 wavelength-division optical transport, concentrating multiple optical wavelengths on fiber infrastructure. The QSFP-DD form factor places the module at the equipment interface while the LC duplex connections provide the optical handoff to single-mode cabling. This interface arrangement suits high-speed switch, router, and transport-platform connections where an 800 Gbps optical path must extend beyond the short-reach distances associated with in-rack copper links. The 2 km reach makes it applicable to links between equipment rooms, rows, or nearby facilities served by single-mode fiber. AXG105142 is distinguished by its 800 Gbps aggregate rate, 2xFR4 optical implementation, two LC duplex connections, and 2 km single-mode-fiber reach. These details matter when matching both the host-side QSFP-DD interface and the existing optical plant. Specify the required optical format, connector arrangement, wavelength plan, and link distance before deployment so that both ends of the fiber connection use compatible interfaces.