I used these for writing awards with ywp.nanowrimo.org. It works if you wear them for a short time. Cheap but fairly durable. They squeeze the head a bit, but I wasn't using this for a costume that I would have to be in for hours. I'd say after one hour, you may want a break because the helmet is more oblong and oval than round. However, it worked great for my purposes, and my students enjoyed wearing them for a class period.
Rating:
[4 of 5 Stars!]