What this MCB does and where it fits
The SENTRON 5SQ2570-0KA20 is a 1P+N miniature circuit breaker with a C-tripping characteristic, rated 20 A at 240 V AC, 50 Hz.
Snap-on DIN-rail mount, 2 width units (36 mm at 18 mm/module). Installation depth is 55 mm from the rail face — standard for flush-mount distribution boards. IP20 finger-safe terminals; wire it into an enclosure if the environment is dusty or damp. Overvoltage category 3 and energy limiting class 3 mean it coordinates with downstream loads and upstream breakers in a typical TN or TT system.