When we skin for days to carve endless powder or make the first summit of an unexplored mountain, we do so with the Mammut Aenergy FL Long-Sleeve as our base. Constructed with smooth, flat seams that follow our every move, this layer won't chafe our skin or unravel under pressure. As we test our grit, the recycled fibers wick and dry at remarkable speed, ensuring we don't overheat or freeze, while the odor-fighting treatment lets us keep our friends close.