The secret of this Reima base layer set is a double-face knit: soft, silky Tencel® against the skin to absorb moisture and give a smooth feel, with wool on the surface for the best possible warmth at the base layer. The Tencel® absorbs moisture away from the skin and helps kids feel fresh. The wool keeps kids warm, even if they become sweaty after busy play. This combination in a kids' thermal set is ideal for thermal comfort - both indoors and outdoors.