Summary

I have made a simple cover for the stewartallen mask that can help provide some protection during the Covid 19 pandemic and other times. This is made for a simple filter. If you want something efficient cut up a vacuum cleaner bag as that can be as effective as a surgical mask (if you have a good fit). In the picture the filter is a paper towel.

This is for the 12 cm mask. I modify the mask to get a better fit and what is shown I have increased the "length" 10% during slicing. X and Z dimensions are unchanged. When you change the dimensions of the mask you also need to change the dimensions of the cover the same amount. I also modified the edge at the top so it will fit even if the groove up there remains small.

As you can see I have put a message on the front for fun. The message on this STL file is simply "staying alive." This comes out 2 mm so you can change filament color so it will stand out as shown