Thermarest BOOST 650 20F/-6C Sleeping Bag

Lightweight three‑season down sleeping bag Therm-a-Rest Boost 650™ with the WarmZip™ centre zipper. Designed for backpackers who want the option of a roomy rectangular bag or a thermally efficient mummy shape.

Main features

• WarmZip™ centre zipper that when cinched pulls insulation around the sleeper to add up to 6 °C of warmth.
• 650‑fill‑power hydrophobic down for a good balance of warmth and packability.
• Multi‑use arm openings for ventilation and easy access without exiting the bag.
• Puffy draft collar and zipper draft tube to reduce heat loss around the neck and zipper.
• YKK anti‑snag and two‑way entry zipper for reliable operation and flexible access.

The Boost 650™ is intended for three‑season backpacking and hiking where you may need to quickly change the bag’s shape and thermal performance between cooler spring/autumn nights and warmer nights that require ventilation.