The Type A residual-current element (30 mA trip threshold) detects sinusoidal AC earth faults plus pulsating DC faults, which covers modern electronics and rectifier-fed loads like LED drivers, washing machines, or variable-speed pumps.
The 1P+N format occupies a single module width (roughly 18 mm), so it fits tightly in a populated enclosure. The neutral pole is switched and protected — no separate neutral bar needed downstream of the device. For a panel-builder or wireman, that saves one bus-bar run per circuit but also means the neutral must be landed on the device's own neutral terminal, not shared across RCBOs.