Layer Arc'teryx's lightweight Atom LT Insulated Pant under your hardshell the next time you want toasty warmth in the alpine. Coreloft insulation brings the warmth without the weight in a compressible package so you can stow the pant in its pocket when you don't need it. The Tinthan shell has a DWR coating for water-resistance in case you don't want to wear the Atom LT as a midlayer. An articulated construction makes sure you can climb and ski with a full range of motion. Arc'teryx also added full-length side zippers so you can get in out and of these pants with crampons and boots on.