The Alpine sleeping bag features the highest quality Ultra-Dry down and a contoured mummy fit for efficient insulation.With space to cater for additional winter gear and 850+ FILL Power, this lightweight sleeping bag is best suited to extreme adventures in cold climates so you can enjoy the outdoors with confidence and peace of mind.FeaturesULTRA-DRY Down 850+ Loft 90% Down Cluster Premium Goose Down certified Responsible Down Standard (RDS)Free-flow zipper system: one full-length YKK® #5 main zip and a half-length zip on the opposite side for ventilationExpedition sizing gives you room to wear extra clothing inside the bagAnatomically-shaped, oversized foot box can accommodate boot linersTechnical shaped hood with hidden drawcords for maximum insulationAn oversized draft collar which fits snugly around your shouldersInternal pocket for phone / GPS / valuablesQuilt-Lock integrated to add extra warmth by adding a Sea to Summit QuiltIncludes lightweight Ultra-Sil compression bag and storage cellTemperature RatingComfort: -19°CLower Limit: -28°C Sea To Summit Alpine -29C Down Sleeping Bag - Regular