Not a gram too much. The Aenergy Light Half Zip Pullover is designed for mountaineering and ski touring all year round. Depending on the outside temperature and level of exertion, you can wear it as either a base or mid layer. It is made from very lightweight Polartec® Power Gridmaterial, which keeps you warm, is elasticated and has a waffle structure on the inside that efficiently wicks moisture to the outside. The half-length zipper allows easier ventilation and lets you quickly slip the pullover on or off. Flat seams reduce unpleasant pressure points for even greater comfort. The Aenergy Light Half Zip Pull: our lightest mid-layer for ambitious mountain sports enthusiasts. Long half-length zipper makes it easier to put on and allows rapid ventilation in warm temperatures Flatlock seams for extra elasticity Lightweight, highly elastic Polartec® Power Grid® fleece with high breathability, excellent moisture management and short drying time Bonded chest pocket with zipper Size & Fit