Features of the Smartwool Women's Merino 150 Baselayer SS Top Our lightest weight Merino jerseyfabric Uses a nylon core to increasedurability while still keeping 100%Merino wool next to skin Raglan sleeve design eliminatesneed for shoulder seams Side seams wrap onto front forenhanced Fit Stretch merrow stitching designedto elevate comfort, range ofmotion, and Fit Fabric Details: 87% Merino Wool / 13% Nylon