A wall plug is a plastic dowel used to enable the attachment of a screw in material that is porous or brittle or that would otherwise not support the weight of the object attached with the screw. It is a type of fastener that for example allows screws to be fitted into masonry walls. They are inserted loosely into a drilled hole, then a screw is tightened into the centre. The screwing action wedges the plug firmly in place, the soft material conforming tightly to the masonry.
Richard Williams plugs suppliers stock a range of wall plugs, including the popular red and brown plugs, along with yellow, blue, M10 and M12.