The Alpha Industries Sierra Long Relaxed Fit Puffer packs RDS-certified 80/20 down under a matte polyester shell built for extreme cold, so the warmth is real rather than a styling choice. Channel quilting keeps the down evenly distributed without adding bulk, and the relaxed, thigh-length cut layers easily while covering more skin than a cropped puffer would. A hidden snap storm flap over the front zipper and a zippered, snap-secured hem seal out wind and snow at the two places cold usually finds a way in. What Our Gearhead(R) Experts Are Saying:"I wore this through a genuinely brutal cold snap and never once reached for another layer underneath, even standing still waiting on a bus. The storm flap kept wind from cutting through the zipper the way it does on jackets that skip that detail."