This is a lense cap designed for the Panasonic Lumix Fisheye lense. Because it is a fisheye, the lense cap holds by friction only. If you lost your cap, like I did, this will probably be very useful.
Print the stl file directly of modify the original openscad file if needed.
Notice that the scad file has a "tolerance" parameter which you can increase/decrease if the cap is too tight/loose.
I obtained a very good fit printing at 0.2mm resolution on a mendelmax 2.0.
I guess printing in black would be ideal for this model...