Beautiful c1934 (based on serial number research) VOIGHTLANDER BRUANSCHWEIG SKOPAR 1:4.5 f/24cm Large Format LENS. mounted on a 4.75" x 4.75" board.  From the estate collection of a long time large format photographer and collector this "as-found" lens has a very smooth and precise aperture adjustment.  Per research, this 240mm focal length lens has a max format sizing of 13x21.  Serial number 803XXX is clearly signed on the barrel and both the front and back of the lens.   Please see photos for more details and toe evaluate condition for yourself