The Mountain Hardwear Power Stretch Zip Tee is a perfect base, mid-layer piece for winter adventurers as well as an outer layer for early fall hikes. With a tailored fit, this shirt is designed to be layered and the stretch fabric never limits your mobility. You will fall in love with this Power Stretch fabric. It wears like iron, breathes well, and always seems to be the right amount of insulation. The 3 inch collar will keep you toasty during the winter and the deep zip front zip will help keep you ventilated when the mercury rises.