Abstract: A fastener for mounting on a support, comprising an axial hollow body, comprising a central part and a plurality of flexible legs, and a base, comprising a central hollow main part and a plurality of projecting rotating legs which pivot around a hinge connecting the leg to the base main part. Each rotating leg has a retracted and an extended position, and in the extended position the leg is pivoted outwardly around the hinge relative to the retracted position. The base has a plurality of holes around the central hollow, the holes adjacent to the rotating legs having a protrusion projecting outwardly. In a mounted position, the flexible legs are inserted into the holes adjacent to the rotating legs, and the central part of the body is inserted into the base central hollow. On insertion, the rotating legs of the base pass from the retracted to the extended position.