[3 x 3 x 0.75"] I LOVE FotodioX adapter and this was my fourth. I bought it to mount a classic Canon 50mm 1.2 LTM rangefinder lens on my Fuji X-Pro1. And when I first did so, the camera wouldn't focus on anything at any distance! But I remembered that I had purchased the lens and its attached Canon VI-T body at a yard sale long ago... and knew nothing about its usage history. So I compared my lens with Google Images and noticed that someone at some time must have opened the lens to clean its common rear-element fogging, and didn't reatach everything properly. So I found instructions on the web, took it apart , put it back together, and it works great! Moral of the story: If one of the awesome FotodioX adapters doesn't work properly for you, also research your lens. It might be the culprit!

[Nikon 1] While relatively inexpensive, this adapter seems well made. Original copy I received did not allow one of my LTM’s to function correctly throughout focus range, With B&H’s excellent customer service, I received a replacement copy. It fits well. Works well throughout focus range.

[3 x 3 x 0.75"] So happy that there is finally an adapter that leaves the index at 12 o'clock. It was the one issue that has bothered me when mounting a Leica thread mount lens to an M body. Be sure to screw the lens on completely, or the index will be off by a hair. It's a well made product that feels like it will last for years.

[3 x 3 x 0.75"] I used this for older lenses that will, at times, get slightly stuck or will not grip the lens enough for easy on / off to the M- mount. Works very well.

[0.1 lb] Arrived much faster than promised. Works great. Allows me to attach old Leica screw mount lenses to my GFX body

[0.1 lb] Works as advertised on a Leica M10 for making backwards-compatible vintage Leica LTM (screw mount) lenses.

[0.1 lb] Solid satisfying build. Bought 2 for some lenses I inherited, 90mm, 85mm, 50mm, 35mm. Mounts great to my 5DMkIV but the lenses are too far from the sensor. Basically like mounting an extension tube when using with a DSLR body

[Nikon 1] I purchased this adapter to mount enlarger lenses to an old Nikon F bellows unit and it does the job. FWIW-this adapter would also allow mounting Leica screw mount lenses to Nikon F bodies. Can't fault the price or the B&H fast shipping.

[3 x 3 x 0.75"] I was going through the ringer trying to find this for a while, especially with this particular set up. Now using this pairing, the focus is in fact not infinite. It is great for a macro and portrait zoning. Otherwise it does not give you the full range without modifications. BUT this adapter does work as advertised. Taking the mount of, i grabbed a pen cap and depressed the switch and rotated clockwise and the adapter came off. I had no wobbles or any issues with my lens staying fixed.

[3 x 3 x 0.75"] It allowed me to mount the old collapsible LEICA ELMAR 50mm f/3.5 from Leica III camera to my M9.