The Outdoor Research Echo Long Sleeve Tee is the reliable, do-everything base layer that somehow works as hard in July as it does in January. AirVent™ technology and ActiveFresh™ odor control keep airflow and freshness in check across long days out, and the ultralight recycled fabric with UPF 15 and flat-seam construction makes it just as at home under a ski jacket as it is on a summer trail run.