these are the underwear and T-shirts for Mormons that are spun on Mormon looms. They ain't Hanes, nor are they Fruit of the Looms or BVDs. They are just "temple garments" and the labeling on the packages say just that.
When I was in Salt Lake City I went to a Z.M.C.I. department store (an LDS counterpart to Lazarus, maybe Macys). In the mens clothing department there were packages of temple garments on the shelves. So one thing I've heard about the Mormon faith was true, I also saw packages of these undies in department stores thruout southern Idaho, where there is a strong Mormon presence.