Men's Smartwool Merino 250 Base Layer Colorblock Crew - SW016353-H87 Essentials Size Based on Calf Circumference

Size Based on Calf Circumference (measure circumference of calf at widest point):

But SOME scientists say it causes eye strain

the Weather Jacket offers 360° ventilation in an ultralight package that's also tear proof and fast drying

thermoregulation

- M 12 = W 13

Men's Smartwool Merino 250 Base Layer Colorblock Crew - SW016353-H87 Essentials Size Based on Calf CircumferenceOur Men's Merino 250 Base Layer Colorblock Crew features 100% responsibly sourced Merino wool made with an interlock knit for enhanced comfort, breathability, thermoregulation, and odor resistance. With shoulder panels and a flatlock seam construction, this base layer brings consistent comfort, as well as reliable warmth and durability, to winter hiking, running, and skiing.