It carries dual breaking capacities: 6 kA per IEC/EN 60898-1 for residential and commercial branch circuits, and 15 kA per IEC 60947-2 / UL1077 for industrial panel applications — the higher figure is the one that matters when you are coordinating with upstream protective devices in a plant distribution board.
The 13 A rating holds at 35 °C ambient; it derates to 12.38 A at 40 °C, 12.05 A at 45 °C, 11.73 A at 50 °C, and 11.38 A at 55 °C. If your enclosure runs hot, size the load accordingly — the 13 A nameplate is only good in a cool cabinet. Not the right curve for motor starting; that is a C or D job. The 2-module width (36 mm) and 76 mm depth fit standard DIN-rail enclosures. Mounting position is any orientation.