The invention concerns an article comprising a first part fitted with flexible lugs, a second part with a foot configured to be moved in rotation in relation to the first part, and with a head to which the foot is connected, and a blocking element, a guide zone and a locking zone configured to allow the rotation then the locking in rotation of the second part in relation to the first part, in order for the article to pass from a waiting configuration, in which the element is in the guide zone and the lugs are in a rest position, to a locked configuration in which the element is in the locking zone, the lugs are in a working position in which they are spaced in relation to the rest position and the second part is blocked in relation to the first part.