Skwala Thermo 350 VestBuilt from the same expedition weight Merino wool as the Thermo 350 Hoody, this vest gives you another option to dial in your optimal insulation. We added a 4 way stretch Primeflex shell across the upper half for increased wind protection, water resistance, and durability. You can wear it as an external layer over a Thermo 150 or Sol Tactical on cool days or use it as an additional mid layer under a shell when conditions get bitter. If youre serious