The 1-pole width (1 module = 18 mm) fits tight panel layouts. Terminal design accepts up to 25 mm² conductor — common for the 20 A feed-through in a sub-distribution board. No external arc-quench clearance needed beyond the standard DIN-rail spacing.
The C-curve characteristic means the magnetic trip activates between 5 and 10 times the rated current (100–200 A for this 20 A unit). That suits it for general-purpose resistive and moderate inductive loads where the inrush peak stays under that band. For highly capacitive loads or long cable runs, verify the peak inrush against the C-curve threshold to avoid coordination issues downstream.