Norrona's most breathable insulating vest the Lyngen Alpha90 Vest is a lightweight layering piece made for ski touring mountaineering hiking winter trail running and cross-country skiing. The Pertex Quantum shell offers light and breathable wind protection while the Polartec Alpha insulation provides breathable insulation that insulates us while also releasing excess body heat and moisture vapor. That makes this vest a nice choice for mid- to high-intensity activities in cold weather.