This Bahtinov mask is used to help focus your lens on the stars precisely. I used a website called https://skeye.rocks/tools/mask/ to generate the mask STL and then added my mounting geometry. This mask uses the existing lens hood retention features to clip onto the front of the lens.
The author remixed this model.
I used the Bahtinov mask generator (https://skeye.rocks/tools/mask/) to make the functional mask geometry. I then used SOLIDWORKS to add on geometry that would allow this part to clip to the front of the lens using the existing lens hood retention features.