Above that, it derates gradually: 19.2 A at 55 °C, 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C. Interrupting capacity is 52.5 kA at 240 V, 32 kA at 415 V, 13.6 kA at 440 V, and 7.5 kA at 690 V. For a 20 A frame, those numbers give plenty of SCCR headroom for most distribution panels — you're not bumping up against the breaker's limit on a typical 415 V line.
The 3VA1020-2ED36-0AH0 measures 130 mm high, 76.2 mm wide, and 70 mm deep. That gives you a dedicated alarm contact for remote fault indication — handy for a PLC input or a panel lamp.