Fotasy Adjustable M42 42mm Screw Mount Lens to Cannon EOS RF Mount Adapter, M42 RF Adapter, M42 Lens to EOS RF, Compatible with Canon EOS R Mirrorless Camera EOS R RP Ra R3 R5 R6 R7 R10

Sturdy, well made, functions perfectly!

Great adapter, fits firmly and strong built.

A great little adapter that allows the rotation to be adjusted so you can get the lens twisted the correct way. Cheap enough to just get one for each adapted lens.

Works like a charm

/////It fits my RF camera, but not my M42 T-Tubes. It feels like it's trying to cross thread. Weirdly, I think the thread is too coarse.//// It is also surprisingly heavy. I'm trying to keep the weight off the back of my telescope the best I can. Correction: There are two different mounts that both get called M42. A correct M42 has a 42mm by 1 mm thread pitch. There is a different thing, which is correctly called a T-mount but is sometimes called M42-.75, and sometimes M42, which is 42mm by 0.75 mm. I was trying to use this M42 adapter to connect to a T-mount telescope adapter. Oops, sorry.