I bought the duvet which claims to be 13.5 tog, but when I opened it, I saw that the filling is minimal and when exposed to light, it becomes transparent. You can clearly see if you hold the duvet in front of a door with daylight and place your palm behind it that your hand is clearly visible. It is empty in most areas, if not everywhere, and feels like just two sheets sewn together. Now, I don't know how it can be 13.5 tog and perform like this. One star for the fabric, which is cotton.