Abstract: A device for fastening an object against a wall as a plug-in mounting is described, which is provided with an externally threaded bolt, onto one end of which a nut can be threaded and on the other end of which, which is at least partially conical and the maximum diameter of which is equal at most to the diameter of the bolt, an expander element composed of two half-shell-like parts is displaceably held. The two half-shell-like expander parts are provided, on their two longitudianl edges which in the mounted state are located opposite one another, with at least two lobes each, which for mutually securing one another axially engage one another adjacently and are held on the conical end by positive adjacent engagement in the radial direction and are disposed on the expander element in such a manner that the expander element parts are transversely symmetrical or in the developed state are point-symmetrical.