Therm-a-Rest Boost 650 0°C Down Sleeping Bag

Adjustable Shape, Season-Busting Warmth

Sleep your way with the Boost 650™ 0 °C Down Sleeping Bag. Its patent-pending WarmZip™ center zipper toggles between a roomy semi-rectangular bag and a thermally efficient mummy shape, adding up to 6 °C of warmth on demand. Zoned 650-fill RDS-certified hydrophobic down surrounds your core, shoulders, and feet, while arm holes, draft tube, cinchable hood, and anti-snag YKK two-way zippers deliver customizable comfort from car camp to alpine basecamp. Made with 100 % recycled nylon shell and liner treated with PFAS-free DWR, it packs light, sleeps big, and performs in three seasons.

Therm-a-Rest Boost 650™ 0 °C Sleeping Bag Features

• WarmZip™ Tech: Converts between semi-rectangular and mummy shapes, boosting warmth by up to 6 °C.
• Zoned 650-Fill Down: RDS-certified hydrophobic down precisely placed around core, shoulders, and footbox.
• Multi-Use Arm Holes: Ventilate, access the WarmZip™, or cocoon yourself without fully unzipping.
• Comfort Enhancements: Cinchable hood, insulated draft tube and collar, and YKK two-way anti-snag zipper.
• Eco-Friendly Materials: Shell and liner are 20D recycled nylon ripstop with PFAS-free DWR.
• Inclusive Sizing: Small, Small Wide, Regular, Regular Wide, Long, and Long Wide options.
• Pack & Storage: Includes compression sack and roomy storage sack.

Therm-a-Rest Boost 650™ 0 °C Sleeping Bag Specifications (Metric)

• Temperature Rating (EN): Comfort 5 °C; Limit 0 °C; Extreme –15 °C
• Fill Material: 650-fill duck PFAS-free hydrophobic down (RDS certified)
• Shell & Liner: 20D 100 % recycled nylon ripstop with PFAS-free DWR
• Zipper: Side-entry, left-hand YKK anti-snag
• Color: Meadow Green
• Country of Origin: Vietnam