works as advertised but does not stay in place [SEP] very surprised that i can really really breathe when using these when i wear my cloth masks had to give only stars tho bc once i start talking it begins to slide down and i have to keep adjusting it does this as i am talking to people and tho they do not know what is going on inside of my mask it is pretty embarrassing to have to adjust what is in the inside of your mask as you are talking to someone