A second layer designed in Powerstretch. It effectively keeps you warm while able to transport perspiration. This full stretch fabric makes sure the layer moves with you and not the other way around while still maintaining a tight fit. Works great under a soft-shell jacket or a down. It’s a brushed inside for added warmth and a smooth outside. A convenient lightweight layer that is easy to bring in a backpack for when you need it. Designed with a collar and two side pockets. This is a smart backup for when the mountain tests you.