This adapter lets you use Canon EF lenses on the Leica L-Mount, e.g. for use on the Sigma fp, the Panasonic S-Series or, of course, the corresponding Leicas :) The lens is meant to be a bit angeled, as I find this more pleasing for video- as well as photo-work. The adapter is aimed at manual- or adapted lenses, as it naturally has no electronical contacts (so you can't adjust the aperture or use autofocus on electric lenses).
The adapter has some "wiggle room" so you will be able to reach infinity, but the scales won't be accurate.
The lens won't be able to lock on the adapter, but the adapter locks well on the camera. I found no wiggle either on the camera- or lens-side.
If you print anything other than black, make sure to black-out the light path! You can use matte black paint or, even better, self-adhesive black velours.
0.2 layer height and 20% infill are enough. Print with support.
I wasn't able to properly test this adapter yet, based on my [NIK adapter](https://www.thingiverse.com/thing:4603615) I don't see why it shouldn't work, though :)