A simple press-on adapter for the Xiaomi Mijia 4K action cam. It allows the usage of threaded 52mm photographic filters in front of the standard, unthreaded lens of the camera by adding an external mount.
V2 file is just a version which prints with minor postproduction refining for my machine tolerances (it varies by less than 1% from the other version's dimensions).
Use supports (better with an interface) to enhance exterior finish; it should also print without supports depending on your machine capabilities.
I used a light infill and 2 perimeters since the cone shape has two walls and light leaking doesn't seem to be an issue.
Press fit the adapter onto the protruding lens of the camera and press or thread the filter onto it. You might have to refine the inserts or to tap the filter mount with a metal filter for it to hold tight.