Smartwool offers an intelligent choice in a versatile layer with this full zip piece. If you wear it as a jacket, you’ll utilize the DWR-treated chest panel that protects you from the elements. As a midlayer, the mixture of wool and synthetic fabric (but heavy on the wool) keeps you warm. Pure merino wool next-to-skin in the arms and back feels soft and helps regulate body temperature and increase breathability, while Smartloft insulation protects your ever-important core. Too warm? The PhD SmartLoft Divide Full Zip is compressible and fits easily into a pack if you take it off during your adventure.