Sleeping bags / Sea to Summit / Reactor liner Spark down mummy sleeping bag
Sea to Summit

Reactor liner Spark down mummy sleeping bag

Updated 2026-08-21

This ultralight down mummy sleeping bag pairs with a Reactor thermal liner to boost overall warmth during chilly backcountry excursions. The combined system adds vital thermal insurance without introducing heavy or cumbersome packing requirements.

Down insulation fills the lightweight chambers to deliver superior loft and reliable heat trapping throughout the night. The efficient mummy architecture reduces dead air space, ensuring body heat warms the interior quickly and effectively.

Ideal for backpackers facing fluctuating mountain weather, this modular sleep setup offers adaptable performance on extended treks. Its lightweight construction ensures easy transport while maintaining high standards of outdoor comfort.

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Reactor liner Spark down mummy sleeping bag
The specs

Specs

Maker
Sea to Summit
Marked

Sleeping bags Ultralight gear Sleeping bag liners

Groups
Sleeping bags Ultralight gear Down sleeping bags Sleeping bag liners
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