Pay in installments of $27.49 with
,
and
Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Aug 19 - Aug 24
Promo Codes Available:
For Your Every Summer RSVP, with Code: SUMMER15
Description
Reactor Fleeceweight Liner Sea To SummitBoost your sleep systems warmth with the Reactor Fleeceweight. Thermolite hollow core fibres and grid fleece trap and reflect body heat, adding up to 8C 14F with minimal weight. The stretch fleece and arm openings allow freedom of movement, while snap attachments fit Sea to Summit sleeping bags for easy access. Easy to clean and quick drying, it features HeiQ Fresh odour control. Using a liner reduces sleeping bag washes, helping preserve loft and
Boost your sleep system’s warmth with the Reactor Fleeceweight. Thermolite® hollow-core fibres and grid fleece trap and reflect body heat, adding up to 8°C|14°F with minimal weight. The stretch fleece and arm openings allow freedom of movement, while snap attachments fit Sea to Summit sleeping bags for easy access. Easy to clean and quick-drying, it features HeiQ Fresh odour control. Using a liner reduces sleeping bag washes, helping preserve loft and extend lifespan.
FEATURES
- Boosts Sleep System Warmth – Reactor Fleeceweight uses Thermolite® hollow-core fibres and grid fleece to trap warmth with minimal added weight
- 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
- Stay Fresh Longer – HeiQ Fresh odour 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 fibres and bluesign APPROVED materials to minimise environmental impact
- Can be used on its own as a lightweight sleeping bag in warm-weather conditions
TECH SPECS
Weight
S: 365g
R: 400g
L: 420g
Certification
RCS - 1114661
Dimensions
Short: 80 x 178cm
Regular: 80 x 193cm
Long: 80 x 198cm
Ideal for
Cold-weather backpacking, Ski touring, (Stand-alone) summer use
Packed dimensions
15 x 15 x 25cm
Recommended user height
S: 170cm
R: 183cm
L 198cm
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- 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
4.7 ★★★★★
Based on 28 reviews
Sort
Product Reviews
★★★★★ 5
Great socks
Size: Medium, Color: (025) Castlerock / Castlerock / Anthracite
Love these little socks. Soft and stay in place, no falling down in my shoe. I will definitely be buying more. Holding up well after multiple washings.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on October 8, 2025
★★★★★ 5
Great fit, no slip
Size: Medium, Color: (025) Castlerock / Castlerock / Anthracite
These looked too small for my feet, but now I love wearing them as they are comfortable and stay on my feet! They look great and the colors are easy to match. Excellent value for the money in my humble opinion.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 28, 2025
★★★★★ 4
Girls socks
Size: Small, Color: Neo Turquoise/Assorted
Girls socks. Quality good
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on October 28, 2024
★★★★★ 5
Size perfect
Size: 4.5-7, Color: Electro Pink/Electro Tangerine/Electro Pink
Perfect fit
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 13, 2026
★★★★★ 5
good, worth the value
Size: Medium, Color: (025) Castlerock / Castlerock / Anthracite
Well it was delivered quick, and all my socks are mostly under armour, as they have developed holes in the heels now, so here i am getting a new set. they fit great, comfortable as usual. some folks may have some sort of issues, while some dont and i cannot complain. worth buying for sure. i recommend
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 22, 2025