The exterior lever handle has to be activated by means of an authorised key. However, in this case the key can be withdrawn again, without deactivating the lever handle.
This is to ensure, that opening the door from the outside is thus possible even without a key.
In practice, this function is used as so called "mechanical daytime release". However it is necessary to ensure, that in the evening the exterior lever handle is deactivated again via the key.
Thus, for example schools, medical practices or law firms can be entered without a key by any person during opening times.
Outside opening hours, access is granted to authorised people only.