400 Gbps is the number. The MMS1X00-N5400 puts it in a QSFP112 package, using four 112G PAM4 lanes and an MPO-12 connector with eight of twelve fibers active. The 1310 nm DR4-class link is rated for 500 m over single-mode fiber, with no in-module gearbox and a smaller body than OSFP.

The desk reads the constraint as mechanical and thermal, not optical. The buyer is constrained by airflow and cage clearance because a 10W maximum power figure and an external heatsink that extends beyond the cage need a clear path in dense GB300 AI Station systems. The document does not prove sustained line-rate throughput, price, shipping status, or a full specification sheet.

Mid-40s Celsius is a lab observation, not a thermal margin. The missing figures are exact temperature, deployment count, availability date, and measured throughput under load. The QSFP112 port check remains the buyer's task.

The buyer is constrained by airflow and cage clearance, not by lane rate, because the module reports a 10W maximum draw and carries an external heatsink. The document proves a 400GbE link, not price, availability, or sustained throughput.

The document leaves out price, shipping status, deployment count, exact module temperature, and sustained throughput under load.

QSFP112 avoids the eight-lane QSFP56-DD gearbox path, but the 10W maximum power and protruding heatsink shift the design burden to airflow and cage clearance. Buyers should verify port compatibility and thermal headroom before treating the module as a drop-in.