The Siemens 3VA1120-4EF32-0JC0 is a 3-pole SENTRON molded case circuit breaker rated for 20 A continuous current across the 40 °C to 55 °C band, derating to 19 A at 60–70 °C. Breaking capacity hits 121 kA at 240 V AC, then drops through 75.6 kA at 415 V, 52.5 kA at 440 V, and settles at 11.9 kA from 500 V to 690 V — so the fault-current headroom you get depends heavily on your system voltage.
Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep — a standard 3-pole MCCB footprint that drops into SENTRON distribution blocks and panel-mount cutouts without re-drilling.
The 20 A frame is sized for feeder or branch circuits pulling up to that load continuously at 40 °C ambient. If your panel sees 60 °C internally, you lose 1 A — still a 19 A continuous rating. The 121 kA SCCR at 240 V is what you'd use for a 240 V distribution board; at 415 V the 75.6 kA still covers most industrial transformer secondary faults.