The Smartwool Women's Merino 250 Base Layer Top is a top-rated choice for women's outdoor base layer tops. It is made with 100% Merino wool, which provides excellent insulation and moisture-wicking properties. The fabric is also naturally odor-resistant, making it perfect for extended outdoor activities. The top has a slim fit that layers easily under other clothing and a crew neck design for added warmth. With its soft and comfortable feel, this base layer top is ideal for cold weather activities like skiing, snowboarding, and hiking.