Versatile Thermal Efficiency with Advanced Infrared Technology

The Sea to Summit Reactor Midweight Liner is the ideal choice for adventurers looking to significantly boost their sleeping bag's warmth without the weight of a thicker fleece. This liner utilizes cutting-edge Thermolite® Pro fabric, which combines hollow-core fibers with infrared-absorbing ceramic pigments. These pigments absorb the heat emitted by your body and reflect it back to you, providing a noticeable thermal boost of up to 6°C (11°F). The stretch-knit fabric is incredibly soft and flexible, allowing the liner to move with you during the night, which is a major benefit for side sleepers and restless movers.

To ensure a perfect fit for every gear setup, we offer the Reactor Midweight in both Regular and Long sizes. The Regular model is optimized for standard-length mummy bags, while the Long version provides the necessary coverage for taller campers, ensuring there are no cold spots at the feet. Both sizes feature an oversized hood with a drawcord to lock in heat and a drawstring base that can be opened for ventilation. Treated with HeiQ Fresh odor control, this liner helps maintain a fresh sleep environment while protecting your expensive down bag from oils and sweat, reducing the need for frequent washes.

Key Features:

• Infrared Thermal Boost: Thermolite Pro technology adds up to 6°C (11°F) of warmth by reflecting radiant heat back to the user.
• Two Size Options: Available in Regular and Long to provide an optimized fit for all body types and sleeping bag lengths.
• Thermolite® EcoMade Fibers: Constructed with 50% recycled materials, offering a more sustainable choice without sacrificing performance.
• Extreme Stretch & Comfort: High-stretch knit fabric ensures the liner doesn't feel restrictive and fits easily inside any bag shape.
• HeiQ Fresh Odor Control: A biocide-free finish that neutralizes body odors to keep your sleep system fresh during long trips.
• Versatile Hood & Base: Features a drawcord hood for maximum heat retention and a drawstring foot opening for temperature regulation.
• Bag Protection: Keeps your sleeping bag clean and extends its lifespan by acting as a barrier against dirt, oils, and perspiration.
• Ultra-Compact Storage: Packs down into its own lightweight stuff sack, taking up minimal room in a backpack or pannier.