Rab's Mythic product family comprises absolute top notch down products from sleeping bags to these shorts. The Mythic Shorts offer tons of warmth with minimal weight - adding insulation to the upper thigh, hip and buttock area is surprisingly effective. The Mythic Shorts are a good choice for ski touring and belaying use, as just a couple of examples. They pack down small and their lofty down offers great insulation. - Extremely high quality RDS certified down fill, treated to repel moisture - Two different material strengths of fabric offer perfect function - The rear has synthetic insulation which resists flattening better than down - Two full length side zippers: the shorts are easy to don and take off without removing your boots - Waist Velcro adjustment helps fine-tune the shorts to work with a variety of underlying apparel