Own the mountain with the Atomic Treeline 2L Flex Jacket. Built from durable, waterproof, breathable, and flexible Pertex fabric, we couldn't give this jacket more adjectives even if we wanted to. Blurring the lines between hard and soft shell the Treeline Flex features the durability of a hardshell with the flexibility and feel of a softshell. 60 80 grams of Primaloft Insulation keep you toasty on even the coldest days. Pack all of this into a shell that was designed by skiers for skiers and you get one cold slaying machine.