Apparatus for floor cleaning, having a cavity that opens on the dashboard, a plurality of mechanically similar interchangeable keys, and suitable to be inserted completely into and operate with said cavity, two or more Hall-effect sensors arranged outside said cavity, at least one first key containing at least one magnet, and at least one second key including at least one respective second magnet, which are in functional correspondence with respective predefined sensors. Said magnets do not interfere with sensors to which they are not geometrically connected, and for this purpose they are aligned on a same straight line, and the insertion of said keys causes a movement of said magnets toward the respective sensors with a motion orthogonal to said straight line.

A magnetic key comprising: a body; a segmented magnet housed within the body; and a ferrous element housed above the segmented magnet. A protective cap for a magnetic key comprising a body; and a ferrous element housed within the body. A locking system comprises a magnetic key and protective cap.