This Review Title is It was unclear whether you should always also wear a mask beneath this or not? and the content is: I think that the most difficult part was getting the clear plastic film off both sides.  Then slipping the plastic eyepiece into place was another hassle.  But they do seem to work.  Not sure they were worth ordering 10 of them, but I am giving them to friends..There are other information for this review, one is This reviewer did purchase it and the other is 0 people think this review is helpful.