The possibility of sterilizing the filter up to 5 times, either by immersion in a 60% alcohol solution, at a temperature of 80°C for 20 minutes, or with ozone or UV. The smallest virus is 200 nanometers, nanofilters capture particles as small as 50 nanometers. Much longer lifespan, thanks to the nanofiltration material used and a single inhalation and exhalation valve, the filter's lifespan is approximately 4 times longer than that of common filter materials for half masks and full-face masks. The package contains 3 filters.