SmartWool® Women's Classic Thermal Merino 1/4-Zip Base Layer Top Plus uses 100% Merino Wool fabric made with an interlock knit for comfort, breathability, thermoregulation and odor resistance. Soft and breathable Merino Wool knit 8" (20 cm) center-front zip with semi-locking slider Back body seam wraps to front Raglan sleeves Flatlock seam construction designed to help minimize chafing Plus Size Fit Product Features: Fabric:250 g/m2 100% Merino Wool, 11.57 oz. SmartWool Women's Classic Thermal Merino 1/4-Zip Base Layer Top Plus