Half zip fleeces are really useful and a great alternative to an often bulky sweater. The Mammut Acongagua ML Half Zip is perfect for walkers and climbers as its constructed from Polartec PowerStretch Pro. This is a warm, breathable fabric with plenty of stretch for freedom of movement and a durable, abrasion resistant outer layer making it a robust piece of clothing, yet soft on the inside. Wear as part of a layering system under a waterproof shell or on its own. Other added features this top is thumb loops on the cuffs to keep hands a bit warmer and a chest zipped pocket for small essentials.