This only works with the Montana Mask if it's printed at 90% Scale. It will not work with the 100% scale version
If you're like me and feel like your mask heats up too much, throw a 50mm USB computer fan on the front for a great way to draw in fresh clean air though your mask filter. This also provides negative pressure to your mask to help keep stray particles from coming in the side.
For use with the Montana Mask, found here:
https://www.makethemasks.com/