Bullet proof...been using these for campouts for about 10 times now and no issues whatsoever. Very firm and the butt does not sink in the middle like some of the other cheaper ones I have pruchased. Don't bother buying the self infallible ones...they don't work at all. You don't even need an electric air blower. I blow up two of these each time we go camping. One is has a rough texture to help from slipping and other side is smooth plastic.