[Canon EF] Works as advertised.

[Canon EF] Utilizing this adapter with M42 lenses allows shooting in multiple modes with the Canon EOS system, but keep in mind that autofocus is not possible with this configuration. Also, focus confirmation features available in Canon EF lenses are not possible to achieve using this adapter. There are some other adapters that are designed to activate focus confirmation, but if you enjoy manual focus as I do then this is the only adapter you need. I would absolutely recommend this lens adapter and B&H Photo to anyone looking to try classic lenses on a modern Canon camera. The quality of the construction of the adapter is superb. It is a beautifully constructed, brass and stainless steel coated ring, and it is very solid. It is noticeably heavier than aluminum adapters. The finish is very polished and detailed, with fine ridges that protrude just slightly over around the edge and center of the ring shaped adapter. Within the center of the adapter is a slightly embossed printing of Fotodiox Pro M42-EOS V 2. My package arrived two days early, and while the box in which it arrived seemed larger than necessary, the packaging was so secure that I would feel very comfortable with ordering a lens or more fragile gear, even a camera from B&H Photo. Mounting the adapter to the camera and lens was incredibly easy. I simply unscrewed the body cap from my EOS body Canon DSLR, screwed the adapter to the camera body, and screwed my classic Yashica 28mm f/2.8 lens to the adapter. The aperture PIN on the Yashica (and many other M42 lens) is pressed against a solid inner lip that protrudes from the center of the adapter, allowing for focusing in infinity for capturing full scenes and distant subjects. I was careful not to over-tighten, and was reassured by the slightly audible click of the EOS body's pin mount locking in place to the perfect-fitting slot cutout in the rim of the adapter. I've been really enjoying the experience shooting with this adapter on my Canon EOS 40D!

[Canon EF] Wonderful mount perfect fit, I definitely recommend this mount if you need one for your lens.

[0.2 lb] I haven't put a lot of mileage on these yet, but they're performing perfectly well under initial usage.

[Canon EF] The adapter works perfectly! The price is great too.

[0.2 lb] I own 4 of these and also the Nikon lens to EF mount, as well as a couple other brands. These adaptors are solid, heavy-duty, accurately machined, and never a worry. For my work I find that computer chips on adapters are basically useless at best and might lock-up your camera body at worst. I have removed the chips from some adapters to improve them. If you are using some cool vintage lenses, you probably know how to add focal length to the EXIF data anyway, right?

[0.2 lb] Easy to screw on, fits my M42 lenses perfectly. EF side locks into my cameras perfectly, tried it out on a Metabones and works just as well. Solid!

[Canon EF] I received this in the mail earlier than the designated time in quite a big box for just a little piece of metal. The early delivery was a plus, and when I connected it to my camera to see how it fit, it was and still is a very tight fit. Make sure the lens is attacked when you connect it, and that you can use the lens to turn the adapter ring to get it out.

[Canon EF] I've bought this adapter so I can use an old Russian lens on my Canon 5D MK3. It is very well made, attaches securely to the lens and the camera body, no light leaks or any other issues, and the price is great!

[Canon EF] Bought a cheapy fun manual 135mm f/2.8 lens made by Bushnell that used a m42 mount. This adapter fit between the lens and my EOS 30D without any trouble. Not tight or loose. Easy to unscrew and remove without any issues of having it getting stick. Well made aluminum adapter.