Mammut's all-season Aenergy Light ML Hooded Jacket is an essential midlayer for late-season tours, cold-weather hikes, and high alpine routes. Anywhere we need the insulating power of Polartec Power Grid fleece, the Aenergy Light comes with us. The grid pattern of the fleece allows airflow and wicking when things heat up, and it traps pockets of heat to keep us comfortable while we pause to soak up the sights.