Soft and lightweight, Mountain Hardwear's expedition weight baselayer, the Lightweight Power Stretch Zip T for Boys is durable enough to take on the rigors of high altitude mountaineering and alpine climbing and remains soft against your skin.Built with Polartec® Power Stretch, this Zip T delivers warm, wicking, quick drying performance and excellent moisture management qualities. The high collar and deep front ventilating zipper provide easy layering Choices and exceptional temperature regulation.