USE AT YOUR ONE RISK. NOT APPROVED BY ANY OFFICIAL ORGANIZATION
This filter cartridge has a socket for a roomba i7 HEPA filter built in and fits on 25mm sockets (see previous mask uploads). These filters can often be found at the local hardware store for about $10 ($30 for 3). This was inspired by the S.A.F.E system from the Medical University of South Carolina. https://web.musc.edu/innovation/covid-19-innovation/safe-cartridge-system-and-masks
Recommend PLA, No Supports, 15% infill (gyroid).
assemble similar to instructions linked above. basically cutout the rubber valve from a kitchen glove using the printable template. superglue the top of the valve rubber, slide the valve cover on and hot glue it in place (for easy removal). snap the filter in, and seal it with hot glue (optional)