It’s a waterproof cover. Not a whole lot to say about it. We only got it because we have a two year old who likes to come visit in the middle of the night to sleep with us. I’m going to assume it works as it’s not really something I was to test. The only complaint I have is our mattress has a cooling gel top on it which I feel like is lost due to the cover. Not the cover’s fault though, just something to keep in mind. It also fit my king mattress with no problems and wraps down really far around the bottom so I don’t think it’ll ever get pulled off.