The Schneider Electric A9N19774 is an Acti9 DPN Vigi RCBO — a combined overcurrent and residual-current device in a single 1P+N module. Its 16 A rated current (In) and C-curve magnetic trip (5 to 10 x In) mean it's sized for general-purpose socket circuits and small inductive loads like contactor coils or lighting ballasts, where the inrush is moderate. The 6000 A Icn breaking capacity at 220–240 V AC, certified to EN/IEC 61009-2-1, tells you it can safely interrupt a fault up to that level without welding its contacts — adequate for most final subcircuits in a residential or light commercial distribution board. The integrated earth-leakage protection (no separate RCCB needed) saves a DIN rail slot and simplifies wiring in the panel. The thermal-magnetic trip unit covers both overload (thermal bimetal) and short-circuit (solenoid) protection. That's a real advantage when coordinating with sensitive electronics or long cable runs.
The 36 mm width (4 x 9 mm pitches) with the neutral on the left matches the standard Acti9 modular footprint.