Light, Packable And Proven, The Atom Lt – An Arc’teryx Icon – Is A Performance Warming Layer For Backcountry Adventures, Alpine Ascents And Downtown Commutes. Refined For Its Next Generation, We Elevated Its Performance And Extended Its Versatility. 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.