Embedded with xylitol crystals for sweat-activated cooling, the Outdoor Research Activeice Full Finger Sun Sleeve lowers your skin temperature as you perspire on summertime runs. ActiveIce fabric not only cools your skin as you perspire, but just as importantly, it dries quickly to eliminate the sweaty sensation of running through oppressive heat. Bicep grippers keep this sleeve from slipping down as you run long distances, and UPF 50+ sun protection shields skin from harmful UV rays.