I kept this lens in hope that I would eventually make use of it on an RB Graphlex, but the focal length is too short and the mirror hits the barrel when I focus on infinity. It's fine on a Speed Graphic, but the depth of field wide open is so shallow that I keep losing focus while I change the back and roll holders don't allow me to focus accurately enough. Time to pass it on. Here's what I do know about it: It's 2 1/4" long and 1 3/8" across. The back-focus length seems to be just under 90mm. It covers 2 1/4 square well, not much more. It's signed on the glass, Jamin et Darlot a Paris, which, I believe, indicates early 1860's for its date. Glass is in good shape, if not perfect, and it comes with one Waterhouse stop, marked 4. There is a flange and an old, cracked wooden lensboard, or camera front, I don't know. The screws are not original but it came with the lens, so I'll include it. The base of the outer sheath will screw into a Copal 1 shutter (mine is from a Polaroid MP4) as well as into the flange. The bad stuff: There is no wheel to adjust focus on the outer sheath. There is no lens shade, though there clearly was at one time. I can't find this lens in the Benjamin French Catalogue from 1890 and I don't know when they stopped making it, nor do I know it's original purpose–perhaps 1/8 plate deguerreotypes? I just know somebody can make better use of it that I can... Got a Hassleblad, or other medium format camera with an FP shutter? This lens might be what you're looking for. The B&W image was taken with it on a 2 /14 x 3 1/4 roll back on a Baby Speed. $150 shipped in CONUS- extra outside the country.