The Siemens 5SY5140-6CC12 is a 1-pole miniature circuit breaker from the 5SY5 series, rated B40 with a 10 kA interrupting capacity at 220 V DC. This is a DC-rated MCB, not a standard AC unit — the 220 V DC rating governs arc extinction and selectivity, so it belongs in a DC distribution panel or a string-level combiner box, not an AC load center.
Snap-on DIN rail mount, 1-pole width. The B40 characteristic curve (trips between 4x and 5x rated current for short-circuit, 1.13–1.45x for overload) is standard for protecting cable runs and general-purpose DC loads.