Nikon F-mount ring

While designing a part to fit my Nikon lens, I started with the lens mount and thought perhaps it might be useful for someone if they had just this to add to their designs
It's just a simple ring that will mount to a Nikon lens and you can design your part from there.
There's a version with a 0.2mm inner brim, since slic3r only adds brims to outer contours. This stabilised the inner contour for me. YRMV.