The B & L Cinephor PM 25 Projector Optical Lens is a vintage 5-inch domed lens designed for Bausch + Lomb projectors. This lens is specifically compatible with Bausch + Lomb projectors, providing clear and precise image quality for slide and movie projections. Its unique domed shape allows for a wide field of view and a smooth curvature to enhance the viewing experience. This lens is a valuable addition for collectors or enthusiasts looking to enhance their vintage projector setups with a high-quality, authentic Bausch + Lomb lens.