These are the second set of sheets by this mfg. that I've acquired.  They are cool, non-wrinkling, easily laundered, and come with deep-deep pockets.  Love these sheets.  They are described as "microfiber" sheets.  But what is the fiber content?  That is not specified and annoys this buyer.  I don't care so much about thread count as fiber content.  My guess is that they are polyester, but if they have any cotton or other fibers in them, one would not know because it is not specified.  Please inform the manufacturer that "Microfiber" is not fiber content.  I'm surprised they can be sold in this country without a specific fiber content.  That said, they fit and are generously cut, feel great, and are extremely durable.