Abstract: The invention relates to a cover plate for installing a handle in a door having opposing faces, an aperture communicating from one face to the other and first and second flanges adapted to lie on the opposing faces. Each flange has an aperture, corresponding at least in part with the aperture in the faces, and first cut-outs and optionally second cut-outs. The aperture and the cut-outs enable at least one different handle to be installed. The handle may have a backset distance of 60 mm, 70 mm, 90 mm, 95 mm or 127 mm, for example. The invention also relates to an adaptor for installing a handle in a door having an aperture communicating from one face of the door to another and cut-outs at the aperture. The adaptor is capable of changing the aperture in the door from one suitable for installing one type of handle to one suitable for installation of a different type of handle. The invention also further relates to use of the cover plate with one or more adaptors.