The SENTRON 5SQ2270-0KA63 is a 2-pole miniature circuit breaker (MCB) from Siemens' SENTRON 5SQ series, designed for 400 V AC, 50 Hz supply. Rated 63 A continuous, it's sized for a sub-feed or a heavy branch circuit in a distribution panel. For most commercial and light-industrial panels fed from a transformer of moderate size, 3 kA is adequate; if your available fault current is higher, you'll need a higher-rated upstream device or a current-limiting MCB. The 2-pole version switches both phase and neutral, with neutral conductor switching confirmed in the design.
Occupies 2 width units (standard 18 mm per unit) on a DIN rail. Installation depth is 55 mm, so it fits standard enclosures without crowding the gland plate. Overvoltage category 3 and energy limiting class 3 mean it's suitable for fixed installations with transient overvoltages up to 4 kV.