Breaking capacity climbs with available fault current: 52.5 kA at 240 V, 32 kA at 415 V, 13.6 kA at 440 V, and 7.5 kA at 690 V. That 240 V number is what you care about on a 240/120 V split-phase panel; the 415 V figure is the one for European 400 V three-phase. Both are high enough to back up a distribution board without cascading. That's a hard requirement on safety circuits or any machine that needs a guaranteed trip on loss of control power.
At 55 °C it derates to 19.2 A, at 60 °C to 18.8 A, at 65 °C to 18.4 A, and at 70 °C to 18 A. If your panel ambient sits above 50 °C — say inside a non-ventilated enclosure or near a heat source — you lose roughly 0.4 A per 5 °C step. Size the upstream conductor and load for the derated figure, not the nameplate 20 A.
Auxiliary contacts and panel fit
Comes with 2 auxiliary switches (HQ type) factory-installed. That gives you two sets of form-C contacts for status feedback — one for the control system, one for a local indicator. No separate auxiliary contact block to order and snap on. The front face carries an IP40 protection class — splash-proof from the front, but no protection on the sides or back (those are inside the panel anyway).