The Sea to Summit Reactor Fleeceweight Liner boosts warmth for cold conditions while staying packable and easy to care for. Made from Thermolite® Fleece, it stretches as you move and includes armholes for unrestricted comfort—whether you’re a side sleeper or tend to toss and turn. It fits inside any sleeping bag and snaps into compatible Sea to Summit bags for secure placement and easier entry/exit.
Using Thermolite® hollow-core fibres in a grid-fleece construction, the Fleeceweight traps and reflects body heat to noticeably enhance your sleep system’s performance—adding up to 8 °C | 14 °F of warmth with minimal added weight.
The liner is quick-drying and easy to clean, with HeiQ Fresh odour control to stay fresher on extended trips. It also helps extend your sleeping bag’s lifespan by reducing the need for frequent washing, preserving loft and long-term performance.
Features:
- Freedom to Move: Thermolite® Fleece fabric and armholes allow unrestricted movement in any sleep position.
- Thermal Boost: Grid-fleece with hollow-core fibres traps and reflects heat—adds up to 8 °C | 14 °F warmth.
- Bag Compatibility: Fits any sleeping bag; snaps into Sea to Summit bags for secure placement and easy entry/exit.
- Extend Bag Lifespan: Reduces washing frequency to maintain insulation loft and long-term performance.
- Easy to Clean: Quick-drying fabric with HeiQ Fresh odour control stays fresher on multi-day trips.
- Ideal for cold-weather backpacking, hut trips, and winter bivvies where extra warmth matters.
Short
Weight: 365g
Fits Up To Height: 170cm
Regular
Weight: 400g
Fits Up To Height: 185cm
Long
Weight: 420g
Fits Up To Height: 198cm
Please Note: We are unable to accept returns of sleeping bag liners for obvious hygiene reasons unless faulty.
All details are in the listing, so please do NOT buy these if you are unsure of suitability.