The Wild Aspen 0™ is engineered for four-season comfort. Its synthetic insulation delivers an excellent warmth-to-weight ratio, while the lightweight, durable micro-polyester shell resists water and abrasion. The inner liner is designed to lock in heat, keeping you cozy all night. A fully adjustable mummy hood and spacious foot box provide added comfort, and the zipper draft tube keeps cold air out for uninterrupted, restful sleep.