The Siemens 3VA2163-5HK32-0AA0 is a SENTRON 3VA2 molded case circuit breaker rated 63 A continuous at 40 °C through 70 °C — no derating needed across that entire ambient span, which simplifies panel layout when the breaker sits near warm busbars or other heat sources. Interrupting capacity hits 187 kA at 240 VAC and 121 kA at 415/440 VAC, dropping to 75.6 kA at 500 V and 3.7 kA at 690 V. For a 63 A frame, the ETU340 gives you selectivity coordination down to the downstream feeder breakers — something a thermal-magnetic trip cannot match.
That 86 mm depth (3.39 inches) is the key fit dimension for shallow enclosures — it clears most 100 mm deep wall-mount cabinets without a gland-plate extension. The 105 mm width (4.13 inches) is the standard 3-pole MCCB footprint; it occupies three 35 mm DIN-rail module positions.