With the Merino 250 quarter-zip, you quit only when you want to. With next-to-skin Merino, it wicks and regulates core temp as a solo piece or smartly layers up when it gets chilly. First Layer fit with no-chafe.. . 100% Merino Wool. Merino 250: Smartwool's warmest base layer. Works as a single layer in cool weather or as a base layer in cold weather. Slim Fit. Interlock knit provides ultimate comfort. 10 (25 cm) center front zipper. Shoulder panels eliminate top shoulder seams. Flatlock seam construction designed to eliminate chafing. Garment Weight: 285 g = 10.05 oz.. Imported. 191931831075 33036000015 SW0NP616