It's a line-protection device — the core job is clearing faults fast enough to protect downstream cables and equipment without taking out the whole panel.
The 25 A rating holds across the full 40–50 °C range and only starts to derate at 55 °C (24 A) and 70 °C (23 A) — so in a warm enclosure you still get nearly the full continuous current.
The 4-pole width (101.6 mm) is a standard 4-module footprint for SENTRON MCCBs — it'll drop into the same busbar or mounting plate as other 4-pole 3VA breakers. No trip indicator, no voltage trigger — just the handle position tells you the state.