Therm-a-Rest on Instagram: "Snuggle up with the Synergy™ Sleeping Bag Liner, designed to add up to 5F/3C degrees of warmth to your sleep system. Tested and proven in our cold chamber, it's
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Best sleeping bag liner: Choose from silk and cotton travel sheets for extra warmth | The Independent
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Litume - All Season Sleeping Bag Liner Adds Up to 27°F / 15°C, Lightweight Mummy Sleeping Sack for Backpacking, Camping
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