The Mammut Haldigrat GTX HS Thermo Hooded Jacket is a lightweight, packable insulated hardshell ski jacket for cold days at the resort and in the backcountry. A GORE-TEX shell blocks wind and moisture. Polartec Alpha active insulation sits under it and holds in warmth. What Our Gearhead(R) Experts Are Saying:"The insulation breathed enough on slightly warmer days that I kept the jacket on, and I opened the underarm vents once a run had me heating up. On the coldest chairlift rides, I kept the vents closed and the jacket held its warmth."