25% off all SmartWool midweight base layers now through Nov. 21! These tops and bottoms for men and women are ideal for stop-and-go activities in cold weather. The Merino wool fabric offers natural stretch and breathability, and it helps maintain comfort whether the climate is warm, cold or in-between. The fabric doesn’t itch and will not shrink. Each piece is made with chafe-free flatlock seams to enhance comfort no matter how active you are.