Slipping on an Armachillo® Undershirt might just be the coolest dang thing you’ve ever experienced. The silky, stretchy 4.9-oz. 91% nylon/9% spandex knit fabric is infused with microscopic jade that disperses heat – giving it cool-to-the-touch comfort unlike any other undies. Plus, it wicks moisture – never feels clammy or clingy like cotton can. And resists odor and mildew so your crew won’t whine about working downwind of you. Improved ultra-smooth side seams stop chafing cold, and a sturdier rib neck never slouches out of shape. Three extra inches in the body keep your undershirt tucked to prevent you from becoming the butt of your buddies’ jokes.