The TM-D trip provides fixed thermal overload protection (L) and fixed magnetic short-circuit protection (I), so there are no adjustment dials; what you order is what you set. Breaking capacity is the headline: 50 kA Icu at 380/415 V AC, 50/60 Hz per IEC 60947-2. In a panel with a transformer or large motor contribution, that rating decides whether the breaker holds or the arc flash escalates upstream. Four poles (4P), with the neutral on the left and neutral protection set to no protection (3D). That configuration is typical for a 3-phase + N distribution board where the neutral is switched but not protected — the neutral pole follows the phase poles without its own overload element.
The 140 mm width, 161 mm height, and 86 mm depth give you the footprint for cutout planning in a panel enclosure. IP40 enclosure protection means it is fine inside a cabinet but not for washdown environments. Mechanical durability is 40,000 cycles; electrical durability ranges from 40,000 cycles at 440 V at half rated current down to 7,500 cycles at 690 V at full rated current. For a distribution breaker that cycles a few times a year under load, that is effectively a lifetime rating. The toggle control is manual — no motor operator or rotary handle in this variant.
The C16N6TM125C carries the TM-D fixed thermal-magnetic trip. If your BOM requires an adjustable electronic trip (Micrologic), that is a different order code in the same NSX160N frame — same physical footprint, different trip unit. No direct pin-compatible alternative exists outside the ComPacT NSX family; the frame size and breaking capacity are specific to this platform.