I have them and use them all the time at the range. They seem to work pretty well, about the same as foam ear plugs, but I can hear conversations better. From what I can gather, the stoppers are used to block noises such as conversations when you are trying to sleep etc. I was kind of skeptical when I purchased them but figured that I could take a $13 gamble. Ive had mine now for about 4 months and haven't had any problems.