Nemo Sonic Down Sleeping Bag 0F/-18C

For three-season mountaineering, late-autumn canoe tripping, or any backcountry adventure where overnight temperatures regularly drop below freezing, the NEMO Sonic 0F/-18C delivers the kind of warmth and comfort that justifies carrying a serious down bag.

Built around 800-fill-power hydrophobic RDS certified down, the Sonic is overstuffed to maintain loft after repeated compression, and the hydrophobic treatment keeps the insulation performing through the condensation and dampness that are facts of life on extended Canadian wilderness trips. The redesigned draft collar and draft tubes form a secure seal at the neck and along the zipper, closing off the cold air pathways that undermine a bag's rated performance in real conditions. The updated profile draws the bag closer to the body to reduce dead air space, and Thermo Gill vents at the core let you regulate temperature during warmer nights or high-output moments without unzipping and losing heat.

The Toester footbox is shaped specifically for foot comfort with waterproof and breathable construction, reinforced by an added layer of synthetic insulation that addresses the cold spots common at the foot end of down bags. Stretch construction at the knees means side sleepers can shift positions through the night without fighting the bag, and an offset zipper creates a thermally efficient seal from top to bottom. Backed by NEMO's Lifetime Warranty.

• Temperature rating: 0F / -18C
• Fill: 800-fill-power hydrophobic RDS certified down
• Footbox: Toester waterproof/breathable with synthetic insulation layer
• Draft system: Redesigned collar and draft tubes
• Venting: Thermo Gill adjustable vents
• Knee construction: Stretch panels for side sleeping
• Zipper: Offset thermally efficient seal
• Includes: Compression stuff sack, mesh storage bag
• Warranty: NEMO Lifetime Warranty