Its 40 A rating at 40 °C and 3-pole construction suit it for protecting feeder circuits in commercial and industrial switchboards. At 415 V it still handles 154 kA, and at 690 V it holds 17 kA. Rated insulation voltage is 800 V, giving headroom for 480 V and 600 V class systems.
Dimensions are 70 mm deep, 76.2 mm wide, 130 mm high. The 76.2 mm width (3 inches) is the standard 3-pole MCCB footprint for Siemens SENTRON 3VA frames — it mounts via screw terminals to a backplate or DIN rail adapter. Verify the existing panel's bus bar spacing and mounting hole pattern against these dimensions before committing the BOM line.
The breaker holds its full 40 A rating from 40 °C through 50 °C. At 55 °C it derates to 39 A, holding there through 60 °C. At 65 °C it drops to 38 A, and at 70 °C to 37 A. Operating ambient range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Maximum power loss is 10.8 W.