We are selling this antique Gundlach Turner-Reich Anastigmat 12'' 18'' 24" f/7.7 convertible brass lens as-is for parts or repair. Its shutter does not fire and one of its blades has been replaced with something paperlike. Its rear thread diameter is 46mm. There are a few cleaning marks on its front and rear elements. There is a small amount of separation around the outer perimeter of both groupings. Please see photos.