This is an Anamorphic Lens Filter to recreate anamorphic lens effects on a non-anamorphic lens.
There are other filters like this, but the shape used in this model creates smoother bokeh than the competitors.
This filter is designed for a 50mm focal length lens with a 52mm filter thread diameter.
However, I included the Fusion 360 file if you would like to adjust the model to fit whatever lens you have.
For mounting option, I suggest attaching it to an old UV filter, but it is pretty forgiving when it comes to the distance from the lens element, so feel free to experiment with the best mounting option for you.
I printed it with a .2mm layer height, but you can use whatever you want. I suggest changing the models thickness in Fusion 360 to a multiple of whatever layer height you want to use.
i.e. for a .3mm layer height use something like 1.2mm thickness (.3mm x 4 layers)