Kaltech photocatalyst-equipped air purifiers, personal disinfection/deodorization units KL-P01X-W 4 units, with pollen countermeasures KL-P01-K 1 unit KL-P02-K 1 unit, with pollen countermeasures KL-P01-W 4 units I bought these for family and relatives during the COVID-19 pandemic, but they hardly used them, so I'm selling them all together. The photocatalyst disinfects the air near your face. Use it for COVID-19, influenza, pollen, and infectious disease prevention. If used in rotation, I think they can last for over 20 years.