Figure 2.

(A) Mask assembly begins with a single 3M 1860 N95 mask. (B) The metal nose strip and elastic straps are carefully removed, and the mask is cut along its horizontal and vertical axes. (C) Each mask quarter is placed in a cartridge face down (any asymmetries can be trimmed) and sealed to the cartridge side using non-toxic adhesive. The filter assembly is then flipped face up and adhesive is used to seal the mask section to the inner edge of the cartridge. Magnified image callouts show the adhesive seals in more detail. (D) Elastic straps are attached through the four fixation points and the assembled cartridge is loaded into the silicone mask base by sliding the cartridge flange into the slot in the mask base.