This is a side-track development of the multi-award-winning line of raceX underwear. We have replaced the cut fibers with eternally long fibers for an even thinner and more silky feel. If you seek winter insulation, this is not the warmest of underwear, but if you on the other hand seek thin super-fast drying underwear for added insulation at high intensity, that will not make you overheat; this is it. Optimal for high-performance high pulse sports. It offers many of the same properties as its older sibling; which is by many chosen for its super elastic construction, very lightweight, and therefore an almost-naked feel when wearing. Supreme breathability.NB: This product runs small in size. Consider buying a size up from what you normally have.