It has a feminine fit with a nice neckline for its look and a great material blend for function. The Womens Siren L/S Sweetheart is 100% Icebreaker! This long-sleeve consists of Merino wool with a small synthetic fiber component. It has the outstanding comfort of Merino with improved drying properties. The soft fabric feels light on your skin. Its very soft, scratch-free, and breathable! Even during high exertion and sweat, the natural properties of Merino wool prevent uncomfortable excessive cooling. Classy! Since Icebreaker gave the Womens Siren L/S Sweetheart a stylish design, you can show it off in everyday settings, too!