Lens Back Cap badges with various popular Focal Lengths.
These are the back caps I purchased from Ali Express. They have a 47.2mm diameter and the caps fit nicely inside the ring. These back caps also come with body caps. If you want to use your own you can resize in slicer to fit using the scale option - but untick ‘uniform scale’.
Add some super glue and your good to go!
The 3MF has the the models face down so you can use your own build plate to get the desire finish you want. The ones pictured here are with the carbon firbre look.
Print with this profile for best results.
Enjoy!