Rated at 25 A and 300 mA sensitivity, it's sized for group incomer duty in a 3P+N 400 V AC network. The 300 mA threshold is the standard for fire protection in commercial and industrial sub-distribution — it won't nuisance-trip on normal leakage from equipment filters and long cable runs, unlike a 30 mA device. The Type A-SI (Super Immunised) classification means it rejects pulsed DC superimposed on the AC waveform and resists nuisance tripping from high-frequency leakage typical of VFDs, UPS systems, and switched-mode power supplies. That makes it a right-sized spec for mixed-load panels where you have both resistive and electronic loads on the same group.
Clip-on mounting onto DIN rail, neutral on the left. The module connects to the MCB by screws — no busbar required. Strip length 14 mm for top connection, tighten to 2 N·m. Occupies 6 x 9 mm pitches, so 54 mm of DIN rail width.