Arcteryx Trino Tight - Men's Front - WindStopper, Back - 90% polyester, 10% spandex Flatlocked seams lie flat for added comfort Composite Mapping Technology strategically places each fabric for most effective protection and climate management Stretch knit fabric on back of legs provides thermal regulation and and air permeable comfort Articulated knees for unrestricted mobility Articulated knees for unrestricted mobility