The Siemens 3VA1125-5EF46-0AA0 is a SENTRON 4-pole molded case circuit breaker (MCCB) rated for 25 A continuous current at 40 °C, using a TM240 thermal-magnetic overcurrent release. It's built for line protection in distribution panels where you need high interrupting capacity across multiple voltage levels — 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and still 17 kA at 500 V and 690 V.
The 25 A rating holds flat from 40 °C through 50 °C, then derates to 24 A at 55–60 °C and 23 A at 65–70 °C. The TM240 trip unit is thermal-magnetic: the thermal element handles overloads (slow response, I²t curve), the magnetic element handles short-circuit instantaneous trip.
The 4-pole width (101.6 mm) is standard for a 4-pole MCCB in this class — it occupies four 25 mm module positions on a DIN rail or mounting plate. Verify the busbar system and phase spacing in your existing panel; if the previous breaker was a 3-pole unit, you'll need the fourth pole's clearance and connection.