Because my leg was stabbed by glass when I was a freshman, the doctor said that the wound should not touch water. At that time, I covered it with plastic wrap, but it still leaked, and the wound felt very uncomfortable when it was scalded by water. After that, I looked at some products on the market. One had water vapor although it would not leak water, and the other had water scalding. Therefore, an air column and a color-changing layer in case of water are added. Please comment!