Brilliant. Used it for my Paperwhite for two weeks on a sandy beach and it kept my Kindle as new. I had no problems with the touch screen changing things itself which some other users have complained about.
If you only want to put your plain Kindle inside it will be fine, but mine is in a clip-on case which is not easy to remove so it would not fit. It would have been useful if they had put the dimensions on the advert. I then bought the Amazon Kindle Holiday Waterproof Case Cover which was fine.