|Keep your core warm and your arms free with the Icebreaker Sierra Mid-Layer Merino Vest. The Sierra Vest is made from lightweight 260 grams of merino wool to keep you warm and naturally odor-free. A zippered chest pocket keeps small items secure and even features a media cord port. There are also zippered hand warmer pockets to keep your hands warm and keep additional gear secure. This lightweight, durable, and naturally odor-resistant vest is the perfect item to wear as a layer under a jacket or as an external garment.