The warmest version of the PRO TREK LIGHT models. Thanks to the combination of RWS merino and Primaloft we get a warm sock without sacrificing lightness. It combines T3 light with SLS technology which keeps the foot dry. The padding in the heel and toe provides comfort during long days of trekking. The combination of Extra Grip and SBS technologies guarantees a perfect fit, avoiding excessive tightening of the calf.