The hard shell layer is the outer layer that protects against wind and rain. The wind- and water protection given by the outer layer, is a prerequisite in order to retain the warming effect of the insulation layer. One very important characteristic of the hard shell layer, is its ability to transport moist out of the garment and let off the surplus of heat from the body. The “breathability” of our ISBJÖRN garments is the key. With the proper insulation underneath, shell garments can be used independent of season and activity.