Smartwool Merino 150 Baselayer 1/4 Zip Shirt - Women'sWe took our popular Merino 150 Base Layer and added a 1 4 zip to it. This Smartwool base layer is amazingly versatile and perfect for unpredictable weatherworking as a single layer when it's warm out and the perfect start for more layers when the sun begins to hide behind the clouds. With Raglan sleeves and a flatlock seam construction designed to minimize chafing, you'll be able to rely on constant comfort all day long.