From mountaineering to winter hiking, the Rab Men's Alpha Flash Jacket is a purpose-built midlayer you'll reach for time and time again. This fleece is made from Polartec's Alpha Direct fabric, which is super breathable and boasts efficient moisture-wicking capabilities to keep you warm and comfortably dry as you move through the mountains. A slim fit and layer-friendly features like streamlined cuffs and flatlock seams prevent that annoyingly bulky feeling under your shell, while stretchy panels on either side won't restrict your adventures.