An article to be blind-fixed to a support provided with an opening of predetermined contour, comprising: - a first part with two flexible lugs each having a free end and being configured to assume, in the absence of stress, a rest position in which they can be introduced without force into said opening of said support, over a first predetermined length from their first free end, and to assume a working position in which they are spaced in relation to said rest position, in order to fix said article to said support, wherein a stop element is configured to rest on said support when said flexible lugs have been introduced into said opening of said support over said first predetermined length, and a body to which each said flexible lug is connected by a second end opposite said respective first free end and which is provided with an opening of predetermined contour which opens between said flexible lugs, and - a second part fitted with a fixing foot having a free end which is configured to cooperate with said first part such that it can be introduced axially from its free end through said opening of said body of said first part, and such that it can be moved in rotation in relation to said first part to cause said flexible lugs to move from their rest position to their working position, and with a head to which said fixing foot is connected via a second end opposite said free end; said article being characterized in that it also comprises at least one blocking element, at least one guide zone and at least one locking zone each configured to receive said at least one blocking element, said at least one blocking element, said at least one guide zone and said at least one locking zone being configured to allow the rotation of said second part in relation to said first part until said flexible lugs reach their working position, then the locking in rotation of said second part in relation to said first part, said article thus moving from a waiting configuration in which said blocking element is in said at least one guide zone and said flexible lugs are in their rest position, to a locked configuration in which said blocking element is in said at least one locking zone, said flexible lugs are in their working position and said second part is blocked in relation to said first part. - a first part with two flexible lugs each having a free end and being configured to assume, in the absence of stress, a rest position in which they can be introduced without force into said opening of said support, over a first predetermined length from their first free end, and to assume a working position in which they are spaced in relation to said rest position, in order to fix said article to said support, wherein a stop element is configured to rest on said support when said flexible lugs have been introduced into said opening of said support over said first predetermined length, and a body to which each said flexible lug is connected by a second end opposite said respective first free end and which is provided with an opening of predetermined contour which opens between said flexible lugs, and - a second part fitted with a fixing foot having a free end which is configured to cooperate with said first part such that it can be introduced axially from its free end through said opening of said body of said first part, and such that it can be moved in rotation in relation to said first part to cause said flexible lugs to move from their rest position to their working position, and with a head to which said fixing foot is connected via a second end opposite said free end;