Sea to Summit | Outdoor Gear To Equip & Inspire

Reactor Lightweight Sleeping Bag Liner

Reactor Lightweight Sleeping Bag Liner - Main image
$39.62 $74.95 In stock

Category: Gear Sleeping Bag Liners

Optimized for minimal weight and maximum warmth, the Reactor Lightweight enhances sleep system performance with advanced Thermolite® Pro fabric, which uses infrared-absorbing ceramic pigments and hollow-core fibers to trap body heat. Adding up to 4°C|7°F of warmth with minimal bulk, it’s ideal for ultralight expeditions. Stretch-knit fabric and articulated arm openings ensure unrestricted mobility. Treated with HeiQ Fresh odor control, it’s quick-drying, machine washable, and helps prolong your sleeping bag’s lifespan by reducing wash frequency.

Features

  • Lightweight and insulative, Thermolite® Pro technology with hollow-core fibers and infrared-absorbing pigments enhances warmth with minimal pack size
  • Freedom to Move – Stretch-knit and shaped arm openings allow unrestricted movement, providing natural comfort throughout your sleep
  • Technical Shape and Hood – Ergonomic design with a fitted hood delivers optimal warmth and comfort without extra weight or bulk
  • Fits any sleeping bag - Stretch fabric means the Reactor Liner fits any shape of sleeping bag
  • Stay Fresh Longer – HeiQ Fresh odor control technology keeps the liner fresh after extended use
  • Sleep System Integration – Snap connectors at the shoulders easily pair with Sea to Summit sleeping bags for quick, hassle-free entry and exit
  • Easy to Keep Clean – Machine washable construction simplifies care and reduces wear on your sleeping bag over time
  • Lower Impact Materials – Crafted with certified recycled fibers and bluesign APPROVED materials to minimize environmental impact
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Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

Express Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

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Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

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Returning an item

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United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

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Customer Reviews (4.6 / 5 · 5 reviews)

Claire ★★★★★

The ceramic-infused fabric actually radiates heat back nicely—I stayed cozy on a 45° night where I usually wake up cold. It packs down smaller than my water bottle, which makes it a no-brainer for a stuff-sack minimalist like me.

Sophia ★★★★★

I was skeptical about the weight savings but this thing actually adds noticeable warmth — the Thermolite Pro fabric has this subtle reflective feel that seems to bounce heat back. Packs down to nothing in my 20L daypack too.

Timothy ★★★★★

Took this on a three-night trip and it genuinely added warmth without any bulk in my pack. The Thermolite Pro fabric feels slick and thin but I woke up noticeably warmer than usual. Zipper never snagged once.