This jacket is made of Grid Tech fleece, a thin and highly breathable material that can squash down to very reduced spaces thanks to its characteristic waffle structure.It can be used for insulation in outdoor activities or even as a warm base layer in less active situations.It stretches and wicks away moisture while still having great insulating abilities.This jacket is also tested for harmful substances according to Oeko-Tex® Standard 100. Compare prices from: Cmp in Men's Clothing