A display unit comprising one or more display panels (5a) and a peripheral frame (2) in which the one or more display panels are mounted and by which the one or more display panels are supported, wherein the peripheral frame comprises a plurality of straight extruded sections (3a-3d) and a plurality of corner sections (4a-4d) linking the straight extruded sections together to form the peripheral frame, each straight extruded section having a substantially solid body defining a substantially flat and inflexible inward facing surface, in which surface a plurality of transversely spaced extruded channels are formed running longitudinally in a length direction of the straight extruded section, each channel in profile having a narrow neck portion and a wider main portion below the neck portion, the display unit further comprising a plurality of channel engaging members each arranged to be slotted into any one of the extruded channels to permit each channel engaging members to be placed in any desired transversely spaced channel and to slide along that channel to a desired longitudinal position, to anchor a mounting for a component of the display unit again the substantially flat and inflexible inward facing surface at one or more transverse locations.