These covers were used on Atlas brand drill presses from the 1940s and 1950s. They were used as column caps, to keep dust and debris from getting down inside the column. They were also used as the cover over the quill spring. I don’t know every model this part will fit, but it is designed for an opening with an ID (inside diameter) of 2.5”. As with my other Atlas parts, this is an extremely faithful replica of the original part.  These parts are UNPAINTED.  A light sanding on top or thin application of filler/glazing compound will eliminate the layer lines and allow a perfect paint job of your choice.