Its job is to combine overload and short-circuit protection in one device, saving a panel row and a set of fuses. At 690 V it still interrupts 4 kA, fine for the occasional 690 V motor circuit. The 45 mm width (three module spaces) is standard for this class — fits a typical motor starter lineup without crowding. Spring-loaded terminals accept up to 2×10 mm² solid or stranded, so no ferrule crimping needed for most panel wiring.
Clearance and mounting
The breaker needs 50 mm clearance above and below for air circulation and arc-quenching — no side clearance required (0 mm left/right). No forward or backward clearance is specified either, so it can sit flush against a backplate or gland plate.