The 30 kA breaking capacity at 400 V AC (IEC 60947-2) tells you it can safely interrupt a fault current up to that level without welding contacts or cascading upstream; under UL 1077 the rating drops to 5 kA, so if the installation falls under UL 489 rules, verify the available fault current doesn't exceed that lower limit. The 4-pole design (3P+N) switches the neutral, which is required on TN-S or TT systems where you need to isolate all live conductors.
Panel integration and environment
Mount it in any position — upright, sideways, even upside-down — which helps when you're squeezing it into a tight gland-plate layout.