The mid-layer plays an enormously important role with the layering principle. It is an insulating layer, the so-called thermal layer, between the first and third layers and also responsible for the transfer of moisture. For insulation and breathability at the same time, DYNAFIT integrates high-tech fabrics from Polartec®. Fleece jackets with Polartec® ThermalPro® are used for cold days on the mountain. Polartec® Powerstretch® hugs the body and is odor resistant, thus ideal for classic ski touring and alpine running. Polartec® Alpha® is the time-tested fabric for intense sports such as ski running, speed touring and speed mountaineering.