It may not feel that chilly outside when you first hit the trail, but as soon as the clouds roll in and the wind picks up, it gets pretty cold in a hurry. Be ready for rapidly changing conditions with the Arc'teryx Trino Jacket. WindStopper fabric on the chest and arms block heat-robbing wind, and the fabric is water-resistant as well to keep you dry if you get caught in an unexpected drizzle or snow flurry. Stretch knit jersey on the back and underarms maintains breathability to allow heat and moisture to escape from the inside out, and it's stretchy for freedom of movement on the trail. An athletic cut keeps the fabric close to your skin for maximum warmth and moisture management, and a drawcord hem prevents chilly drafts from blowing in.