Sugoi RS Short Sleeve Base Layer Large WhiteSugoi RS Short Sleeve Base Layer. Sugoi has applied IceFil technology and a Xylitol treatment to their RS Short Sleeve Base Layer for enhanced temperature regulation and performance that you can actually see! Xylitol treatment cools your skin as you sweat, then sends the sweat to the fabric surface for quick evaporation. This is visualized by the fabric turning white as you perspire, and then returning to its original pattern as you cool down. IceFil technology reduces fabric surface temperature and offers maximum UV protection. Fits perfectly under a tight jersey or can be worn by itself in hotter weather.714642895060