Eliminate the need to stop and change layers as you close in on the summit, with this highly breathable and adaptable synthetic insulated jacket. It combines PrimaLoft® Gold Active+ insulation, which breathes and insulates through peaks and troughs of activity, with low-bulk Thermic™ stretch fleece side panels that offer superb mobility and make the jacket easy to layer. The breathable yet wind-resistant Pertex® Quantum Air fabric deflects windchill while responding to your output, keeping you comfortable on tough ascents in mixed conditions. The result is lightweight, packable active insulation you can wear as a warm layer or technical outer, from the dawn start to the summit push.