This is a functional first or base layer (base layer/thermal underwear) often used for outdoor activities, running, or winter sports. Model specifications and features: Brand: Paradox. Material: A blend of fine Merino wool and synthetic fibers (polyester, spandex), offering excellent moisture-wicking (thanks to Drirelease FreshGuard technology), quick drying, and heat retention. Construction: Stand-up collar with a short zipper (1/4 zip) and anatomically cut sleeves (raglan style) featuring contrasting red flatlock seams to prevent chafing. Details: Small reflective brand logo on the chest and the "PARADOX" brand name on the sleeve cuff.