Review title is A must for wearing a cloth mask [SEP] This is a lifesaver when wearing a cloth mask! It stops the fabric from sucking into your nose and making it hard to breathe. Another pro- washable and reusable! I run mine through the dishwasher on the top rack. Only other thing I have noticed is they do build up some condensation from your breath, making it a little sweaty. But that is so worth being able to breathe easier.