It protects a single-phase final subcircuit against both overload/short-circuit (via the C-characteristic magnetic/thermal trip) and earth leakage (via the 300 mA Type A residual current sensor).
Ratings and their meaning for the buyer
Rated at 32 A at 30 °C ambient, the RCBO derates linearly as panel temperature rises: 30.4 A at 40 °C, 28.8 A at 50 °C, 27.2 A at 60 °C, and 24.64 A at 70 °C. If the distribution board runs warm — say 50 °C inside the enclosure — the continuous load must not exceed 28.8 A, not the 32 A nameplate. The 300 mA residual trip threshold is a standard value for general-purpose socket-outlet circuits where a lower 30 mA threshold would cause nuisance tripping from cable capacitance or inrush. Type A detection covers sinusoidal AC and pulsating DC residual currents, which is the minimum requirement for circuits with single-phase rectified loads (e.g., washing machines, LED drivers).
The IP20 rating applies only when installed in a distribution board with connected conductors — the device itself is not sealed for exposed installation. Halogen-free and silicon-free materials suit environments where outgassing must be minimized (e.g., clean rooms, medical facilities).