Now I know why you all say these covers don't last. I just went down to Leslie's to look a their blue covers. They say they are 12 mil, but they are nowhere near the same as the ones I used to buy from them. Their current line of covers are super light, and the bubbles are thinner than the cover itself, and are soft like bubble wrap! The bubbles on the covers I used to get from them were much stiffer and seemed to be made of the same material as the cover itself. Do you any of you have covers where the bubbles are stiff? If so, were did you get yours?