3M 7500 mask exhalation valve

thingiverse

This compact design is engineered to filter your exhaled breath just like you inhale it. With this configuration, the mask starts protecting those around you if you're infected without realizing it. HOW TO USE: Simply add filtering material such as a surgical mask (ensure correct orientation) or cotton disks (not recommended) and snap two parts together. I recommend replacing filters before each use. Installation process: Check out the step-by-step guide at https://youtu.be/UxBEbYAQROk. In some countries, health authorities prohibit respirators unless they protect those around the wearer. Using this filter box with a standard surgical mask or other filtering material can help you breathe filtered air and demonstrate to law enforcement why you're allowed to wear a respirator. Feel free to customize this design to suit your needs. I printed it from PETG, but you may need to scale down the second part by 1% for a snug fit. Please note that all DIY mask modifications are used at your own risk. To ensure a secure seal, consider using a sealant (PTEE liquid or ribbon) to prevent any gaps where infected air might escape. This design comes in three versions: 1. Surgical mask only - the smallest and fastest to print, designed for use with surgical masks. 2. Large box - shown in photographs, suitable for use with cotton and surgical masks simultaneously. 3. Test design - adapted for 12-hour shifts, currently being tested; it's large and designed to keep mask pieces dry longer.