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.

An electronic lockbox with a single sensor that can detect both the position of a key compartment component (or a movable key bin) and the presence of a removable key fob (attached to a building key). The key compartment includes a first magnet and the removable key fob includes a second magnet. The single sensor can detect the presence of neither magnet, the first magnet alone, or both the first and second magnet together. If neither magnet is detected, then the key compartment (movable bin) is open. If only the first magnet is detected, then the key compartment (movable bin) has been closed without the removable key fob. If both the first and second magnets are detected, then the key compartment (movable bin) is closed with the removable key fob inside the movable bin.

An electronic lockbox with a single sensor that can detect both the position of a key compartment component (or a movable key bin) and the presence of a removable key fob (attached to a building key). The key compartment includes a first magnet and the removable key fob includes a second magnet. The single sensor can detect the presence of neither magnet, the first magnet alone, or both the first and second magnet together. If neither magnet is detected, then the key compartment (movable bin) is open. If only the first magnet is detected, then the key compartment (movable bin) has been closed without the removable key fob. If both the first and second magnets are detected, then the key compartment (movable bin) is closed with the removable key fob inside the movable bin.