So I just got these a few days ago and I've been trying them out in different masks. I really like them! And I couldn't stand the ones that just sit on my face under the mask. These didn't touch my face at all (although DH says I look like I have a beak, LOL!

). They fit really well on the majority of the cotton masks I wear but there was one mask that the bracket didn't work on at all (wrong size) and they were a little difficult to slide them on - I used a screwdriver to help open it up a little. Those clips may loosen a bit as I keep wearing them. The air was still warmer under the mask than it was outside of the mask, but I didn't have to worry about the fabric so close to my mouth. My new chiffon etsy mask arrives tomorrow so I'll check back once I'm able to try them together!