Rangefinder polarizing filter holder

### What this is
This is a holder for a 25mm polarizing filter in the spirit of the long discontinued Kenko Rangefinder Polariser. It prints upright quickly without supports and fits Leica M hotshoes as well as other standard hotshoes.

### Whom it's for
The problem this Thing solves is the following: When using a rangefinder camera you don't see through the lens. You frame your composition through a viewfinder next to the lens. When using filters, this is usually an advantage because your vision is unaffected by coloured or strongly tinted filters. However to effectively use a polarizer one must orient it correctly to achieve the desired effect. This is not easily possible on a rangefinder camera. There are swing-out gadgets that swivel out the filter in front of your viewfinder but they are very expensive and don't fit every lens. Another solution are oversized polarizers mounted on the lens through which you can see from the viewfinder but those struggle with reflections and are unw