The 5SL6132-7MB: Width is 18 mm — one modular unit. That matches the standard SENTRON 5SL footprint, so it clips onto the same DIN rail as any other 1-MW MCB in the family. No extra clearance needed beyond the usual front-access for the toggle and the IP20 finger-safe terminals. Mounting position any, which simplifies layout in a crowded enclosure.
The 6 kA rating at 400 V AC per EN 60898 is the standard domestic/commercial interrupting capacity; for industrial panels with higher fault current you'd step up to the 10 kA variant (5SL4120-7CC shares the same physical footprint but rates 20 A at 10 kA). The 32 A rating at 30 °C is the thermal reference; no derating table is published for elevated ambient, but the 75 °C max operating temp suggests the bimetal is calibrated for standard 30 °C reference conditions.