The Siemens 5SJ3125-7RC is a 1-pole miniature circuit breaker from the Retail line, rated 25 A with a C characteristic and a 4.5 kA breaking capacity.
Panel integration
Snap-on DIN rail mount, standard 1-pole module width (roughly 18 mm per pole). The Retail line shares the same footprint as the broader 5SJ family, so it slots into existing distribution boards without re-spacing.