The ABB 2CSF204006R1250 FH204 AC-25/0,03 is a 4-pole residual current circuit breaker (RCCB) rated 25 A with 30 mA sensitivity, Type AC.
The 25 A continuous rating means it handles the full load of a typical lighting or general-purpose socket circuit without nuisance tripping. Type AC means it responds only to sinusoidal AC residual currents; it won't detect pulsating DC or smooth DC faults, so if your load includes variable-speed drives, LED drivers, or EV chargers, you need a Type A or Type B RCCB instead.
