SKU: 34114421068

Sea To Summit Reactor Lightweight Liner - Regular

Sale price$62.96 Regular price$69.95
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USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 15 - Jul 20

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Description

Sea To Summit Reactor Lightweight Liner - RegularOptimized 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 4C 7F of warmth with minimal bulk, its ideal for ultralight expeditions. Stretch knit fabric and articulated arm openings ensure unrestricted mobility. Treated with HeiQ Fresh odor control, its quick drying,

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.

Best Use: Backpacking, Cycle touring, Paddle touring

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

Tech specs


Regular
Weight 9.0oz
Dimensions 76.0 x 31.5 in
Packed Size 3.9 x 7.1 x 3.9 in

Material(s)
100% Post-Consumer Recycled Polyester; Stuff Sack: 100% Polyester

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 34114421068

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Solid athletic socks at a great price. Not too thick, not too thin. Second time I've purchased them. They last longer than most socks I've used in the past too. Only concern is the sizing. I may be reading the sizing chart wrong, but for my size 13 feet it says XL are the correct sock size. I've ordered Large twice and they're perfect. I would imagine the size Large socks would also fit up to size 14 shoe, but probably need to go with XL if foot is lager than 14.
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Reviewed in the United States on April 12, 2026
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Kevin March
Los Angeles, US
★★★★★ 4
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Size: Large, Color: (035) Steel / White / Black
Comfortable fit perfect
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I recently picked up a pair of Under Armour socks, and they’ve quickly become my go-to choice for daily wear and workouts. From the first wear, the fit felt snug and supportive without being too tight. The fabric is lightweight yet durable, and it does a great job wicking sweat — keeping my feet dry even during longer runs or intense gym sessions. One of the things I appreciate most is the arch support and cushioning in the right places. It adds just enough padding where I need it, especially under the ball and heel of the foot, which makes a noticeable difference on days when I’m on my feet a lot. The socks also have a nice breathable mesh pattern that improves airflow.
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