Sea to Summit Reactor Fleeceweight Sleeping Bag Liner
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Product Description
FLEECEWEIGHT INSULATING SLEEPING BAG LINER WITH THERMOLITE® HOLLOW-CORE FIBRES, GRID FLEECE WARMTH, STRETCH COMFORT, HEIQ FRESH ODOUR CONTROL AND SLEEP SYSTEM INTEGRATION
The Sea to Summit Reactor Fleeceweight Sleeping Bag Liner is built to boost your sleep system’s warmth in cold conditions. Designed for cold-weather backpacking, ski touring and stand-alone summer use, it adds serious thermal performance while keeping your sleeping setup cleaner and more adaptable.
Reactor Fleeceweight uses Thermolite® hollow-core fibres and grid fleece to trap and reflect body heat. When paired with a quality sleeping bag and mat, it can add up to 8°C of warmth to your sleep system.
The stretch fleece fabric and shaped arm openings allow unrestricted movement while you sleep, giving a more natural feel inside your sleeping bag. A technical shape and fitted hood help deliver optimal warmth and comfort without unnecessary weight or bulk.
Snap attachments integrate with Sea to Summit sleeping bags for easier access and better alignment, while the quick-release entry makes getting in and out simpler. HeiQ Fresh odour control helps keep the liner fresher after extended use.
Machine washable, quick drying and made with certified recycled fibres, the Reactor Fleeceweight Liner helps reduce sleeping bag washes, preserve loft and extend sleeping bag lifespan. Available in Short, Regular and Long models, it is the warmest option in the Reactor liner range.
BOOSTS SLEEP SYSTEM WARMTH
- Designed to add serious warmth to your sleeping bag setup
- Can add up to 8°C of warmth when paired with a quality sleeping bag and mat
- Best suited to cold-weather backpacking, ski touring and cooler camping trips
- Can be used on its own as a lightweight sleeping bag in warm-weather conditions
THERMOLITE® FLEECEWEIGHT WARMTH
- Thermolite® hollow-core fibres help trap body heat
- Grid fleece construction helps reflect warmth while keeping weight controlled
- Designed to add warmth with minimal added weight
- Warmest option in the Reactor liner range
FREEDOM TO MOVE
- Stretch-knit fleece fabric allows natural movement while sleeping
- Shaped arm openings help prevent restriction inside your sleeping bag
- Comfortable for sleepers who move or change position overnight
- Fits comfortably inside a range of sleeping bag shapes
TECHNICAL SHAPE AND HOOD
- Ergonomic design improves warmth and sleeping comfort
- Fitted hood helps retain warmth around the head
- Technical cut reduces excess fabric and unnecessary bulk
- Designed to work cleanly inside mummy-style sleeping bags
SLEEP SYSTEM INTEGRATION
- Snap connectors at the shoulders pair with Sea to Summit sleeping bags
- Quick-release front entry makes access easier
- Designed to stay aligned inside compatible Sea to Summit sleeping bags
- Works as part of a layered sleep system for changing conditions
EASY CARE AND LONGER BAG LIFE
- HeiQ Fresh odour control helps keep the liner fresher after extended use
- Quick-drying construction makes it practical for travel and multi-day trips
- Machine washable construction simplifies care
- Helps reduce wear and washing on your sleeping bag over time
- Helps preserve sleeping bag loft and extend sleeping bag lifespan
FABRIC COMPOSITION
- 100% post-consumer recycled polyester
- Stuff sack: 100% polyester
- Stretch fleece construction for comfort and movement
- Thermolite® hollow-core fibre technology
TECHNOLOGY
- Thermolite® hollow-core fibres help trap body heat
- Grid fleece construction helps reflect warmth with minimal added weight
- HeiQ Fresh odour control helps keep the liner fresher for longer
- Snap connectors support Sea to Summit sleep system integration
SUSTAINABILITY DETAILS
- Crafted with certified recycled fibres
- bluesign® approved materials
- Helps reduce sleeping bag washing frequency
- Helps preserve sleeping bag loft and extend sleeping bag lifespan
CARE
- Machine washable
- Do not use fabric softener
- Air dry or machine dry on a cool to warm cycle without dryer sheets
- Dry fully before storing
- Store clean and dry between trips
| Specification | Details |
|---|---|
| Product Type | Fleeceweight insulating sleeping bag liner |
| Available Models | Short, Regular and Long |
| Best Use | Cold-weather backpacking, ski touring and stand-alone summer use |
| Material | 100% post-consumer recycled polyester |
| Stuff Sack Material | 100% polyester |
| Thermal Technology | Thermolite® hollow-core fibres and grid fleece |
| Added Warmth | Up to 8°C when paired with a quality sleeping bag and mat |
| Odour Control | HeiQ Fresh |
| Construction | Stretch fleece fabric |
| Shape | Technical mummy-style shape with fitted hood |
| Arm Openings | Shaped openings for unrestricted movement |
| Sleep System Integration | Shoulder snap connectors pair with Sea to Summit sleeping bags |
| Entry | Quick-release front entry |
| Care | Machine washable and quick drying |
| Best Use Conditions | Cold nights, winter camping, ski touring, cold-weather backpacking and stand-alone summer use |
The Sea to Summit Reactor Fleeceweight Sleeping Bag Liner is available in Short, Regular and Long models. Choose the model that best matches your height and sleeping bag length.
| Model | Weight | Dimensions | Packed Size | Recommended User Height |
|---|---|---|---|---|
| Short | 365 g | 178 x 80 cm | 25 x 15 x 15 cm | Up to 170 cm |
| Regular | 400 g | 193 x 80 cm | 25 x 15 x 15 cm | Up to 185 cm |
| Long | 430 g | 206 x 80 cm | 25 x 15 x 15 cm | Up to 198 cm |
How much warmth does the Reactor Fleeceweight add to a sleeping bag?
The added warmth depends on your sleeping bag and mat setup, but the Reactor Fleeceweight can add up to 8°C when paired with a quality sleeping bag and mat.
What is the Sea to Summit Reactor Fleeceweight Sleeping Bag Liner best used for?
It is best used for cold-weather backpacking, ski touring, winter camping, stand-alone summer use and improving sleeping bag hygiene.
What sizes are available?
This liner is available in Short, Regular and Long models.
What is the Reactor Fleeceweight made from?
It is made from 100% post-consumer recycled polyester, with a 100% polyester stuff sack.
Which Reactor liner is the warmest?
The Reactor Fleeceweight is the warmest option, followed by the Reactor Midweight, then the Reactor Lightweight.
Can the Reactor Fleeceweight be used for backpacking or biking?
For bikepacking frame bags or ultralight backpacking, the Reactor Fleeceweight may be too bulky. Larger winter camping backpacks generally offer enough space.
Can the Reactor Fleeceweight be used on its own?
Yes. It can be used on its own as a lightweight sleeping bag in warm-weather conditions, although it is not designed as a full sleeping bag replacement in cold conditions.
Can the Reactor Fleeceweight be machine washed and dried?
Yes. Reactor liners can be machine washed without special soaps. Do not use fabric softener. Air dry or machine dry on a cool to warm cycle without dryer sheets.
Which Reactor Fleeceweight size should I choose?
Choose Short for users up to 170 cm, Regular for users up to 185 cm and Long for users up to 198 cm.
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