On its own or over a t-shirt, the Minus 33 Mid-Weight 1/4 Length Zip Top is an excellent choice for starting your cold weather ensemble. Made with natural 100% 18.5 Micron Merino Wool, this zip top features flat lock seams that prevent chafing to ensure you can wear them longer with less irritation. The 230 g/m2 Interlock knit construction creates warmth without losing any comfort. No need to hang dry or mess with dry cleaning, the Minus 33 1/4 Length Zip Top is machine washable and machine dryable.