This Backpacker Editors’ Choice award-winning big-mountain bag offers exceptional warmth and tuneability with a reduced environmental impact. Now updated for 2019 with a redesigned draft collar and draft tubes to create a secure seal against cold air; overstuffed 800FP hydrophobic, RDS certified down; and an updated profile and shaped foot box, the Sonic™ continues to rock out as the King of Comfort from basecamp to summit.
The contoured hood with drawstring cord creates maximum thermal efficiency, and stretch construction at the knees allows side sleeping. Toester™ footbox is tailored for foot comfort, waterproof/breathable, and includes a layer of synthetic insulation to reduce cold spots.
