Sonic is built to be the only bag you need from -20°F to 40°F. The Backpacker Editors’ Choice award-winning big-mountain bag offers exceptional warmth and tuneability with a reduced environmental impact. This bag features our next-generation Thermo Gill™ vents, with a new multistage zipper system that dramatically increases the usable temperature range of the bag and allows fine-tuning of comfort from within. Sonic’s chevron baffle construction better compartmentalizes down, eliminating migration and keeping the down evenly lofted. (Not to mention, it looks awesome.)

Sustainability:

• Constructed with 100% recycled, bluesign® approved shell and liner fabrics

Design & Details:

• Award-winning design updated for even greater warmth retention and adjustability across temperatures
• Overstuffed with premium 800 FP hydrophobic down that is PFC-Free and 100% Responsible Down Standard (RDS) certified, ensuring humane treatment and traceability throughout the supply chain
• Toester™ waterproof/breathable footbox utilizes a layer of synthetic insulation to protect the down and deliver maximum toastiness for toes
• Second-generation Thermo Gill™ vents extend the comfort range with a new multistage zipper system
• Offset zipper creates a thermally efficient seal while an updated profile secures warmth closer to the body
• Chevron baffle construction better compartmentalizes down for more uniform loft and down migration prevention
• Stretch construction at the knees for comfortable side sleeping