As one of the favorite selections in the Atom Series, this piece really is a keystone of  synthetic insulated midlayer options. While light and synthetic, this versatile jacket works as a midlayer and/or a standalone. Both comfortable and streamlined with a trim fit. The Coreloft™ Compact 60 insulation retains heat when wet and withstands repeated packing and unpacking. The soft, durable Tyono™ 20 face fabric resists wind and weather, and stretch fleece side panels improve ventilation and freedom of movement.