These lightweight insulated pants are the perfect layer to pull on over the top of your active layers when stopping to belay, or take a short break, or when setting up camp. The fully separating leg zippers mean that they can be put on without having to take off boots, skis or crampons. As lofty as 3 layers of fleece at a fraction of the weight. They can also be used as part of a sleep system when traveling with a light bag, or when conditions get really cold.