The Men's Smartwool Merino 250 Baselayer Crew is a tried and true layering piece that has been updated to improve functionality and aesthetics. An interlock 100% merino wool knit offers comfort, breathability, thermoregulation and odor resistance. Shoulder panels eliminate top shoulder seams while the flatrock seam construction minimizes chaffing while wearing the Merino 250 Baselayer Crew.