Customizable Optical Lens Holder

I needed a holder for different sized lenses to measure their focus. Thus this thing. It's openscad, nothing fancy. Uploading images of printed holders once I make them ;)
The stl files are sized according to their filenames and basically just samples for different sizes.
I'll create other holders for mirrors or prisms in the near future and upload those here as well

Update:
a newer verision is currently WIP at https://www.thingiverse.com/thing:3377831 its main additional feature is the a