With a trim, performance shape and shingle style construction, the Eureka Spero 20 Sleeping Bag: 17 Degree Synthetic offers maximum warmth in a minimal package that's ideal for extended time out on the trail. The 40D polyester taffeta shell fabric offers tough resistance against the wear and tear of the trail, while the Eureka Synthesis synthetic insulation delivers cozy sleeping situations in temps as low as 17-degrees Fahrenheit. A full-length, insulated zipper draft tube with anti-snag guard stops unwanted cold air from sneaking in. The anatomic hood design ensures that no space is wasted, and it is insulated along with the chin baffle to seal in that precious warmth. And when morning comes around and it's time to pack up, the stuff sack compresses for an exceptionally easy carry.