Memorial Day Sale
Up to 30% off this year’s gear
More Ways To Save
Memorial Day special deals
Reactor Fleece Mummy + Drawcord Sleeping Bag Liner
Style & Size:
Quantity
Join Summit Club+ and
Cozy up and dial in your comfort with the Reactor Fleece Mummy + Drawcord Sleeping Bag Liner
What Our Gearhead® Experts Are Saying:
"I brought the Reactor Fleece Mummy + Drawcord Sleeping Bag Liner on a late October trip where temps dipped further than expected, and it genuinely saved me from a miserable night. The shoulder zippers made it easy to vent when I overheated on the climb in, and the drawcord footbox locked in warmth the moment temps dropped after midnight."
The forecast said low thirties, and your sleeping bag says it's rated to twenty, so on paper, you're fine. But anyone who has ever woken up stiff and shivering at two in the morning knows that paper and reality do not always agree. The Sea to Summit Reactor Fleece Mummy + Drawcord Sleeping Bag Liner exists for exactly that gap, slipping inside your existing setup to add a meaningful layer of warmth without adding meaningful weight to your pack.
Sea to Summit built the Reactor Fleece liner around hollow-core Thermolite Pro fibres arranged in a grid-pattern fleece that traps heat more efficiently than a standard flat fabric would. Shoulder zippers give you a quick escape valve when you're too warm, and the drawcord footbox lets you cinch down or open up depending on conditions. HeiQ Fresh odour control keeps things tolerable on longer trips, and the mummy shape means warmth stays where your body needs it most. It also integrates directly with Sea to Summit's Free-Flow Zip sleeping bags, making it a natural pairing if you're already in that ecosystem.
Details
- A fleece mummy liner that boosts sleeping bag warmth
- Hollow-core Thermolite Pro fibres trap heat in cold conditions
- Grid-pattern fleece construction maximizes warmth retention
- Shoulder zippers let you vent quickly when temps swing
- Drawcord footbox seals in warmth or opens for airflow
- Mummy shape delivers thermal efficiency where you need it most
- HeiQ Fresh odour control keeps the liner fresh on long trips
- Compatible with Sea to Summit Free-Flow Zip sleeping bags
- Item #STSZ0A4
- Responsible Collection
- Recycled/Repurposed
- Material
- 60% Thermolite EcoMade (100% recycled polyester), 40% polyester, HeiQ Fresh anti-odor treatment
- Shape
- mummy
- Stuff Sack
- included
- Stuff Size
- 9.8 x 3.5 x 5.5in
- Dimensions
- [compact] 78 x 31.5in, [standard] 85 x 31.5in
- Claimed Weight
- [compact] 13.8oz, [standard] 14.8oz
- Activity
- hike & camp
- Manufacturer Warranty
- lifetime

Your Ally In Every Adventure
Since 1991, Sea to Summit has been there for every adventure. Designed to be the perfect balance of clever, packable, and light, Sea to Summit products encourage self-reliance anywhere.
Related Categories
Related Searches
Sea To Summit Reactor Fleece Mummy Sleeping Bag LinerBest fleece sleeping bag liner for fall campingThermal boost sleeping bag liner for cooler nightsCustomizable ventilation sleeping bag linerMummy shape sleeping bag liner for comfortLightweight sleeping bag liner for backpackingDurable fleece liner for outdoor adventuresEco-friendly sleeping bag liner with recycled materialsBreathable fleece liner for mild weather campingCompact sleeping bag liner for easy packingOdor-resistant sleeping bag liner for extended tripsVersatile sleeping bag liner for hiking and campingLearn more about Reactor Fleece Mummy + Drawcord Sleeping Bag Liner



