Sierra Designs Zissou Plus 30 Degree Down Sleeping Bag, Online Lime/Sleet Grey Polyester Traditional mummy shape. Unique integrated quilt: Dual zip and trapezoidal shaped quilt provides bed-like comfort in warm weather. Side wall baffles prevent down migration, keeping you warm. Anti-snag zippers. DriDown 700-fill duck down insulation stays dry 10-times longer than untreated down and dries 30% faster.