Convenient, Economical,  and Efficient
I like that i can use this filter in one of my usual cloth masks which are only one layer of material (generally from Old Navy) and have confidence that I have a bit more protection from viruses and allergiens and also I like it because a cloth mask will get moist and makeup laden with an hour or two of wear, but with the filter in there I can simply change out the filter when it gets yucky and put a new one in the mask and wear it the rest of the day.
Rating: 4 stars