Sea To Summit Spark SpIII

All Spark sleeping bags are characterized by their ultra-lightweight, minimal pack size, and excellent thermal performance. The SpIII features continuously sewn vertical box chambers that include an extra amount of down and reduce cold spots. The expedition size ensures extra space for additional layers of clothing. The vertical chambers in the chest area optimize the distribution of down and prevent shifting. The full-length zipper with two sliders allows for easy entry and provides variable ventilation. A zipper channel, a hood, and a thermal collar prevent heat loss. Ultra-Dry Down is a PFC-free, water-repellent treatment for down that is used in all Sea to Summit sleeping bags. UltraDry Down retains over 60% more loft, absorbs 30% less moisture, and dries 60% faster than untreated down, meaning that the down insulates better even in damp conditions. The treatment also inhibits bacterial growth and extends the lifespan of your sleeping bag. The UltraDry Down treatment is an environmentally friendly application.