For high-output pursuits, the lightweight 180 GSM merino pieces are the perfect choice. Offering excellent breathability, moisture-wicking properties, and a soft next-to-skin feel, they're built for action. Constructed from a 95% merino wool and 5% Spandex blend, they provide elite performance with total freedom of movement. Eberlestock LS Lochsa Merino Short Sleeve Black X-Large LSBX Top