REI Co-op Everyday Briefs - Size Large, Color Red. Fabric: 92% Polyester 8% Spandex. Features: Classic fit of a brief with a soft fabric blend of polyester and spandex that breathes well, moves moisture away from skin and dries quickly Elastic waistband fits comfortably while you move Functional fly Field tested while cycling, climbing, hiking, running, sleeping and, of course, everyday wearing and washing