I don’t like wearing masks in general but also know they are a necessity when in an environment with particulates in the air that you don’t want to breathe in, such as sanding dust. They work very well compared to others I have used, especially the ones without an output vent. They don’t cause my eye protection to fog up as much as most others I have used. I bought these over others with vents even though they are a tiny bit more expensive. That might matter if your purchasers care about how much it would cost for thousands of them. I don’t use that many so the few pennies more are ok. They are heavy duty and catch all the dust. They are easy to put on and I don’t mind them when I am working nearly as much as others I have used. I think I will throw away unused others that aren’t nearly as good. I don’t notice any fine dust getting through the material. The vent works very well. I like these masks even though I hate wearing masks.