Spring skiing or summer camping? The year-round Merino 150 base layer long sleeve is game for either thanks to the body temp regulating and no-stink properties of Merino. Featuring Core Spun technology, Smartwool wrapped Merino around a nylon core for added durability while still keeping the comfort of ultra-soft Merino next to skin. Smooth flatlock seams help minimize chafing and offset shoulder and side seams to lie smoothly beneath pack straps. 87% Merino Wool, 13% Nylon Core. Slim Fit. Merino 150 is Smartwool's most versatile layer with enhanced durability and ultimate breathability. Quick drying, it works as a solo layer in warm weather or as a baselayer in cool weather. Raglan sleeve design removes shoulder seams. Flatlock seam construction designed to eliminate chafing. Garment Weight: 170 g = 6 oz. Imported.