The Schneider Electric A9D18810 is an Acti9 IKQE RCBO — a combined residual current breaker with overcurrent protection, rated 10 A at 50 °C with 100 mA earth-leakage sensitivity and a C-curve trip characteristic.
The 10 A rating at 50 °C means this RCBO is sized for a final subcircuit feeding lighting, general-purpose sockets, or small resistive loads — not motor circuits or high-inrush equipment. The 100 mA earth-leakage threshold is for protection against fire risk rather than personal shock — most socket circuits in a TN system would use 30 mA for personnel protection; this is typically specified for feeders, fixed equipment, or circuits where the earth-leakage background is higher. It complies with BS EN 61009-1, the harmonized standard for RCBOs in the UK and EU. The limitation class 3 means it limits let-through energy well — good for cable protection downstream.
At 18 mm width (2 modules), it fits the Acti9 modular grid; leave space for a padlock with Ø 4 mm hasp if you need lockout. Tighten to 2 N·m. The IP20 rating means it is for indoor, dry environments only — no washdown or outdoor exposure.