[Aluminum] My headline says it all. It is an adapter of excellent quality and works as expected. I used this on a 35mm Elmar, 50mm Elmar, and28mm Hektor. All worked fine and achieved infinity focus. The adapter seemed a bit tight when locking in but it works. Warning to those who want to use collapsible lenses like the 50mm Elmar: do NOT collapse the lens! The barrel extends so far to the back that it hits the area around the sensor. A hard tap to the front of the lens will damage the sensor area inside your Sony A series camera. I would strongly advise against it. The old lenses look great on my A9 sensor. The Elmar lenses are particularly beautiful and will give any modern lens a run for its money. My Hektor is the most underperforming of the lot but still the rendering is sublimely old-timey. Feels almost like an Ansel Adams picture if printed in black and white (not that I am comparing myself to the old master!) It costs more than its competitors but do yourself a favor and get a good adapter once and not have to worry about having to get more in the future. You've spent a lot of money on your camera and lenses (these old LTM's are getting more expensive on eBay thanks to the resurgence of film) so why cheapen out on an adaptor?

[0.195 lb] Very nicely made adapter with proper fit to Leica SL series cameras. I purchased this to connect my SL2-S to an astronomical telescope focuser using a 2 nosepiece. What I learned upon receipt is the difference between M2 (1.0mm thread pitch) and T2 (.75mm thread pitch)... most astronomical fittings are T2 and will not attach properly to M42 without an M2-T2 adapter. These exist but are not easy to find. Fortunately I did source one and the adapter now works perfectly for my intended use.

[0.195 lb] Got this to adapt my collection of Takumar lenses for my new S1H. This adapter feels perfectly sturdy and does what it was designed to do. Extra meaningful because it let me adapt lenses left from my late grandfather. Definitely the adapter to get for Leica L-mount cameras.

[0.195 lb] Top built quality, focus infinity excellent . Connection smooth and firm .

[0.195 lb] This is an excellent adapter. Very solid and well built and fits tightly... no wobbles of any sort.

2 errors from Urth on this adapter though: I have added photos highlighting this

1. On the Nikon Z teleconverter mount, there is a small notch in the adapter ring which is absent on the back side of the Urth adapter.

Therefore if you intend to use this adapter with Nikon Z teleconverter and Nikon F lens (Nikon's FTZ adapter cannot be used because the adapter hole does not allow the Z teleconverter protruding element to pass through); so if you intend to use this adapter with Z teleconverter, you will have to grind out the notch either in the teleconverter mount ring (not recommended) or grind a notch into the back side of the Urth adapter... recommended as it costs only 39$.

2. Additionally, Urth has unnecessarily put a very small screw on the back side of the adapter which also prevents it from screwing into the Nikon Z mount. We need to remove this screw as well.

Urth needs to made these 2 updates to their future adapter manufacturing runs.

I am now able to successfully use a Nikon Z camera plus Nikon Z teleconverter + Urth adapter and Nikon F lens in manual focus mode.

[Leica L] At the time of purchasing this product (and as I write this) there was only one review (which gave it 1 star). I feel somewhat compelled to balance that out. I'm using it with two older f-mount lenses (Nikon & Tamron) and they both work great! They fit incredibly well with a solid connection and I have no complaints whatsoever with this product. It does it exactly what it's supposed to do, and it seems to be made to last. Enjoy!