Abstract: An inspection apparatus for measuring the flange of a can prior to forming the flange into a radially outward directed flange includes a light generating element for generating generally parallel light rays of a light beam along an axis and a refractor for receiving the parallel light rays and separating the light rays into a first light beam and a second light beam. The first light beam propagates generally along the axis into the can and is reflected within the can to produce a lighted image of the inside edge of the flange. The second light beam propagates at an angle relative to the axis to illuminate and produce a lighted image of the outside edge of the flange. A video camera generates image data from the lighted images, and a data processor interprets the image data. The refractor includes an outer cylindrical member and an inner cylindrical member disposed in a cavity extending through the outer cylindrical member.