The Siemens SENTRON 5SY4101-6 is a 1-pole miniature circuit breaker with a B tripping characteristic, rated at 1 A. It fits one modular width (18 mm) on a DIN rail, with a depth of 76 mm and height of 90 mm. Breaking capacity is 10 kA per IEC/EN 60898-1 and 35 kA per IEC/EN 60947-2, so it handles fault currents up to those levels depending on the standard your installation follows.
IP20 with conductors connected — fine for enclosed panels, not for open wet areas.
Ambient temperature range is -40 °C to +75 °C, but the rated current derates above 35 °C — at 50 °C it's 0.9 A, at 60 °C it's 0.85 A. If your panel runs hot, account for that drop in the load calculation.