Review (3/5): OK product, but didn’t fit me. One size only, so may or may not work for you.
These were a great idea when everyone was still wearing cloth masks (I’m now wearing N95’s when needed). These are one size soft plastic inserts, so they’re probably fine if they fit your face. They were too big for me and I couldn’t get a comfortable fit. It’s tricky finding a way to keep them in place in your mask; I used a good double sided tape all over the outside (the part that would face the mask) then put it on my face and put the mask over it to fit it in the right position. It works fine, but it just never was comfortable for me (I have a really small face) so it poked too low on my chin or it would ride up my nose and let air out that fogged up my glasses. But for the price, it’s worth a try if you’re required to wear a mask. It does let you breathe easier and keeps it out of your mouth. My mom and pop use these same ones and like them just fine.