The disclosure relates to an optical security feature that is based on a single axis alignment of mirrors or facets in a structured surface that forms a micro mirror array. In an aspect, a device is described that includes a reflecting structure on a first layer, where the reflecting structure has a top surface with multiple embossed facets arranged in a spatial orientation that produces a flat ring optical effect upon incidence of light. In another aspect, a method for making the device is described that provides a reflecting layer and produces the reflecting structure on the reflecting layer with multiple facets arranged in the spatial orientation to produce the flat ring optical effect. In yet another aspect, an apparatus for making the device is described that includes a pressing device and a stamping device to transfer a pattern of the reflecting structure to a reflecting material.