Rated 40 A with 300 mA sensitivity, Type AC, it sits on a DIN rail in the outgoer position of a distribution board. The 73.5 mm depth plus the MCB height means it fits standard 4-module (7 x 9 mm pitches) enclosures; plan for 91 mm height clearance above the rail.
The 40 A rated current (In) matches the MCB it plugs into — don't oversize the block relative to the breaker. The 300 mA sensitivity is instantaneous (no time delay), so it's suited for general fault protection on circuits where nuisance tripping from leakage isn't a concern. Voltage-independent tripping means it doesn't need a neutral-to-earth voltage to operate — it will clear a fault even if the supply voltage is lost.
Mounts via clip-on to DIN rail. The bottom tunnel terminals accept 1 to 35 mm² rigid cable (or 1 to 25 mm² flexible with/without ferrule). Strip 14 mm, torque to 3.5 N·m. The plug-in electrical connection to the MCB is made through the busbar comb — verify comb compatibility (bottom side marked YES). IP20 finger-safe when installed in an IP40 modular enclosure.