Lovely old rack and pinion focus lens. This antique black painted brass 9'' (229mm) large format lens's precise focal length and maker are not marked therefore we are unsure what they are. We determined that its focal length is near 9'' by focusing light through it. Its rear thread is 55mm. it does not come with a mounting ring. The exterior of the lens has some scuffing and scratching on it. Its glass has haze inside of it, but it is free of any fungus or separation to its elements.