I bought this to use with my Canon EOS R and never got around to using it. It's pretty heavy. It looks like a Petzval style pinion and rack lens. The lens hood has a dent, but the glass is all good. The aperture works great, the focusing know needs a little help. I'm also including a m65 to m65 helicoid and a m65-EOS adapter. All you need is a m63 to m65 adapter. I think this is a large format lens.