Technically both. I just find it laughable that you believe in a product that attempts to beat a whitetail's nose, but you call a product that attempts to beat a whitetail's eye's a "gimmick". I personally don't use either, but as you stated earlier, use scent free (not scent eliminating) laundry detergent and air dry my hunting clothes.I'd venture to guess that an outstanding numberof hunting clothes manufactured today do noteven need UV treatment, simply because it was taken into very serious consideration a decade ago. Imjust trying to make a point that I would be more skeptical of a product that feeds me the "scent free" story vs. a UV killer. We both know that the deers olfactory sense are stronger than its visual or even auditory senses. Im just making the point that the rods and cones in a deer's eye gives them the ability to distinguish ultraviolet colors. I don't believe in making assumptions and calling it a tested hypothesis...