Wearing a neck gaiter may be worse than no mask at all, researchers find - The Washington Post

Of the 14 masks and other coverings tested, the Duke University study found that some easily accessible cotton cloth masks are about as effective as standard surgical masks, while neck gaiters may be worse than not wearing a mask at all. https://www.washingtonpost.com/lifestyle/wellness/mask-test-duke-covid/2020/08/10/4f2bb888-db18-11ea-b205-ff838e15a9a6_story.html