'A' type RCDs available in 2 pole or 4 pole, 30mA or 100mA operating current. Used in EV chargers, offices and anywhere there could be pulsed DC residual currents.
'A-Si' type RCDs available in 2 pole or 4 pole, 30mA operating current. Used in circuits with lots of electronic noise, including banks of PCs, fluorescent lighting, inverters etc.