The Nike ACG Lava Flow Therma-FIT Hooded Jacket uses Therma-FIT ADV and PrimaLoft insulation to hold warmth while a water-repellent finish keeps rain and damp conditions out. A regular, hooded fit covers the head and torso without restricting movement underneath a pack. When the temperature climbs, the jacket folds into its own internal pocket and clips to a pack with the ACG tribiner, so there's no need to carry it loose or stuff it in with other gear. What Our Gearhead(R) Experts Are Saying:"I shed this jacket mid-hike once the sun gets high, pack it into its own pocket, and clip it to my bag with the tribiner without breaking stride. That kind of packability is what keeps me from leaving a warm layer behind in the first place."