The 45 mm width and 117 mm depth mean it occupies one standard 45 mm module on the rail — no extra space needed for a separate base.
The 3RH2262-4BW40 is rated for 10 A at 24 V and 6 A at 230 V — those are the thermal current values that govern the contact's continuous carry capacity at those voltages. The AC switching rate is 10,000 operations per hour, so it keeps up with high-speed cycling on a packaging line or conveyor interlock.
That means it fits in tight enclosures where the rail is oriented vertically or the panel layout forces an angle.