A must have addition to your mask
I use this product inside my surgical mask when exercising and under cloth masks when I am going to be talking.  It keeps the mask from being sucked into my mouth.  I teach water aerobics, and before I got this insert, I was miserable.  Now I can breathe well and lead my classes without having mask fabric in my mouth.  I regularly recommend this product to all my students.  These particular inserts are cheap and do the job.
Rating: 5 stars