The C16BN4FM is a Schneider Electric ComPacT NS1600bN new generation basic frame — a 4-pole, fixed-mounted, manually operated air circuit breaker rated 1600 A at 50 °C. It carries an N breaking capacity code: 70 kA Icu at 415 V AC, with the full IEC 60947-2 curve up to 85 kA Icu at 220/240 V AC and 65 kA Icu at 690 V AC. This is the bare frame without a control unit or protection module, so it ships as a mechanical switch intended for distribution duty in a backplate-mounted panel.
The 1600 A continuous rating at 50 °C sets the thermal capacity for a main or feeder breaker in a large distribution board. The Icw of 32 kA for 3 seconds allows selective coordination with downstream devices: the frame holds through a delayed fault long enough for a branch breaker to clear.