Instrument that allows locking and unlocking a lock. Declarations of co-ownership generally contain a provision compelling the co-owners to give a duplicate key of their apartment and to communicate, if necessary, the access code of their alarm system. The objective is to allow the members of the board of directors or the condo manager, in case of an emergency, to access the apartment of an absent co-owner without having to resort to the services of a locksmith, or having to break down the door in the event of a loss.