A trustworthy insulation layer is indispensable in any winter outdoor pursuit. You need to be certain that it will keep you warm and comfortable even when wet, and it needs to be versatile enough to perform multiple duties. The high tech Mammut Eigerjoch Light Insulated Jacket fits this description, and is perfectly suited for backcountry and mountaineering expeditions in winter climates. The outer fabric on this jacket is the venerated Pertex Quantum, a featherweight, wind blocking, water resistant, breathable material. Polartec Powerstretch panels on the sides and back combined with high reach sleeves and thumb loops give the jacket exceptional range of motion when you're reaching overhead. The extremely breathable, lightweight, and fast drying Polartec Alpha insulation is very effective at regulating body temperature during high exertion and stop and go activities. Due to the design of this jacket and the exceptional robustness of the Pertex Quantum fabric, The Eigerjoch can be worn either as an insulation layer or as an outer layer in the place of a softshell. Two concealed hand pockets and a zippered chest pocket provide storage if indeed the jacket is being used as outerwear.