That TM designation means fixed thermal and magnetic trip elements — no interchangeable trip unit, so the 20 A rating is locked at order. The breaker holds its full 20 A rating from 40 °C up through 50 °C ambient; it derates to 19.2 A at 55 °C, 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C. Breaking capacity is the headline here: 187 kA at 240 VAC, 121 kA at 415 VAC, 75.6 kA at 440 VAC, and 17 kA at 690 VAC. At 415 V (common IEC industrial voltage), 121 kA still gives headroom for most distribution boards. The 690 V rating at 17 kA is lower but still adequate for many 690 V motor control centers. This is a 3-pole breaker with an undervoltage release (UVR) built in — the release design is listed as 3VA9608-0BB24. It also ships with 2 auxiliary switches HQ.
Front IP40 protection means it's splash-proof from the front but not sealed for washdown environments; mount it inside a cabinet, not exposed.