Reactor Midweight Sleeping Bag Liner
SIZE
Reactor Midweight Sleeping Bag Liner
REG
Fair D Canada
1651 Chemin de l'Industrie
Beloeil QC J3G 6S8
Canada
Sea to Summit Reactor Midweight Sleeping Bag Liner
A thermal sleeping bag liner designed to boost warmth, improve comfort, and help keep your sleeping bag cleaner during repeated field or backcountry use.
Backpacking / Touring
Thermal Liner
Up to 6°C / 11°F
Thermolite® Pro
The Reactor Midweight is built with Thermolite® Pro fabric that uses hollow-core fibers and infrared-absorbing ceramic pigments to help trap and reflect body heat with minimal bulk.
Product Overview
Designed for backpacking, cycle touring, and paddle touring, the Reactor Midweight adds warmth to a sleep system while remaining relatively compact and easy to maintain. Sea to Summit states it can add up to 6°C / 11°F when paired with an appropriate sleeping bag and sleeping pad.
The liner also features stretch-knit construction, shaped arm openings for freer movement, a technical hood, HeiQ Fresh odor control, machine-washable construction, and snap connectors at the shoulders for compatibility with Sea to Summit sleeping bags that support integration.
Key Features
- Thermolite® Pro fabric for improved warmth retention
- Far infrared ceramic pigment technology
- Hollow-core fibers help trap body heat
- Stretch-knit construction for better sleeping comfort
- Shaped arm openings for unrestricted movement
- Technical hood for added warmth
- HeiQ Fresh odor control treatment
- Machine washable and quick drying
- Made with recycled fibers and bluesign APPROVED materials
Ideal Applications
- Cold-weather sleep system upgrades
- Backpacking and lightweight touring
- Cycle touring and paddle touring
- Keeping sleeping bags cleaner in the field
- Layered sleep systems for variable temperatures
- Users who want added warmth without carrying a heavier sleeping bag
Technical Specifications
| Specification | Regular | Long |
|---|---|---|
| Best Use | Backpacking, Cycle touring, Paddle touring | Backpacking, Cycle touring, Paddle touring |
| Type | Thermal Liner | Thermal Liner |
| Material | 100% Post-Consumer Recycled Polyester; Stuff Sack: 100% Polyester | 100% Post-Consumer Recycled Polyester; Stuff Sack: 100% Polyester |
| Weight | 12.3 oz / 350 g | 12.9 oz / 365 g |
| Dimensions | 76.0 x 31.5 in / 193 x 80 cm | 78.0 x 31.5 in / 198 x 80 cm |
| Packed Size | 4.5 x 7.5 x 4.5 in / 11.5 x 19 x 11.5 cm | 4.5 x 7.5 x 4.5 in / 11.5 x 19 x 11.5 cm |
| Fits Up To Height | 6 ft / 185 cm | 6 ft 6 in / 198 cm |
| Warmth Increase | Up to 6°C / 11°F | Up to 6°C / 11°F |
Why Choose the Reactor Midweight
This model sits in a practical middle ground: more thermal performance than a lightweight liner, but less bulk than heavier fleece-style options. Sea to Summit’s FAQ identifies the Reactor Fleeceweight as the warmest, followed by the Reactor Midweight, then the Reactor Lightweight.
For Fair D Canada, this makes it a strong fit for layered cold-weather sleep systems, expedition kits, winter camp setups, and customers wanting a simple way to extend the operating range of an existing sleeping bag.
