We believe these were made for some of the Kodak 35mm slide projectors. We know it fits the Kodak Ektagraphic III ATS projector. Assembly includes a Halogen 300 Watt, 82 Volt GE #EXR projection lamp (used in Kodak Carousel slide projectors), a dichroic mirror, 50mm x 45mm x 2mm thick, and a DCX condenser lens, 50mm wide x 55mm long with a focal length of 65mm. The mirror passes the heat straight thru and reflects the light thru the condenser lens. Front has a small door labeled "Reading Light" that opens to expose an opaque Fresnel lens that lets out some light from inside. We see the projection bulb alone selling for more than our price for the entire assembly. Unused. Also, great for parts and creative projects.