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

Reactor liner Spark down mummy sleeping bag four

Updated on 2026-08-21

Designed with an included Reactor thermal liner, this ultralight down mummy sleeping bag maximizes cold-weather adaptability. The supplementary liner boosts core warmth, making it easier to manage fluctuating nighttime temperatures in the wilderness.

Advanced down fill ensures high loft and superior insulation capacity while preserving a lightweight footprint. The ergonomic mummy design hugs the contours of the body to prevent cold spots and retain warmth efficiently.

This comprehensive sleep configuration supports backpackers seeking reliable performance and minimal pack weight on the trail. It offers a balanced approach to outdoor sleeping comfort through smart material integration.

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Reactor liner Spark down mummy sleeping bag four
The specs

Specs

Maker
Sea to Summit
Marked

Sleeping bags Ultralight gear Sleeping bag liners Fleece liner

Groups
Sleeping bags Ultralight gear Down sleeping bags Sleeping bag liners Fleece liner
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