What the DC rating means for fit
This is a DC-only breaker — the 'C1UC' suffix signals the DC trip characteristic. Unlike an AC-rated MCB that relies on zero-crossing to extinguish the arc, a DC breaker must handle sustained arcing because DC current never naturally crosses zero. The S202M-C1UC uses a permanent-magnet blowout or arc-chamber design to force the arc into a splitter stack. If your panel feeds a 24 VDC or 48 VDC control bus, a 125 VDC telecom supply, or a string of PV panels, this is the right protection class.
Snap-on DIN-rail mounting — no screws, no bracket. The S202M footprint is 2 modules wide (about 36 mm). Wire termination uses the standard tunnel-type screw terminals; torque to the value printed on the side label. If you're replacing an older S200-series unit, the busbar comb positions and the auxiliary-contact slot are identical, so it drops into an existing distribution block without re-terminating the bus.