--- product_id: 630870203 title: "Reactor Insulated Sleeping Bag Liner" brand: "sea to summit" price: "£71.55" currency: GBP in_stock: true reviews_count: 13 category: "Sea To Summit" url: https://www.desertcart.co.uk/products/630870203-reactor-insulated-sleeping-bag-liner store_origin: GB region: United Kingdom --- # Drawcord footbox for customizable comfort Mummy shape for thermal efficiency Thermolite EcoMade fibers for max warmth Reactor Insulated Sleeping Bag Liner **Brand:** sea to summit **Price:** £71.55 **Availability:** ✅ In Stock ## Summary > 🔥 Stay warm, fresh, and unstoppable on every adventure! ## Quick Answers - **What is this?** Reactor Insulated Sleeping Bag Liner by sea to summit - **How much does it cost?** £71.55 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/630870203-reactor-insulated-sleeping-bag-liner) ## Best For - sea to summit enthusiasts ## Why This Product - Trusted sea to summit brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Next-Level Warmth:** Hollow-core Thermolite fibers trap heat without bulk, keeping you cozy in 32°F+ temps. - • **Lifetime Confidence:** Backed by Sea to Summit’s lifetime guarantee—gear up knowing this liner’s got your back for years. - • **Odor-Free Adventures:** HeiQ Fresh tech keeps your liner smelling clean, even after back-to-back trips. - • **Tailored Thermal Control:** Mummy design with shoulder zippers and footbox drawcord lets you dial in your perfect microclimate. - • **Seamless Sleep System Integration:** Drawcord footbox pairs perfectly with Sea to Summit’s Free-Flow Zip sleeping bags for zero drafts. ## Overview The Sea to Summit Reactor Insulated Sleeping Bag Liner uses advanced Thermolite EcoMade fibers in a grid-pattern fleece to maximize warmth retention while maintaining lightweight comfort. Its mummy shape and adjustable footbox drawcord optimize thermal efficiency and fit, integrating seamlessly with select Sea to Summit sleeping bags. HeiQ Fresh odor control technology ensures lasting freshness, making it an essential 3-season companion backed by a lifetime guarantee. ## Description Product description WE INVENT GEAR THAT ENABLES FREEDOM AND SELF-RELIANCE IN ANY ENVIRONMENT Camp Kitchen Ultra-portable camp kitchen gear includes lightweight and collapsible cookware, dinnerware, utensils and more. Sleep Systems Sleeping pads, bags, liners, and pillows . . . when you're weighing your options, the most important factor is the value of a great night's sleep. Dry Storage Space-saving stuff sacks and dry bags keep your camping gear dry and protected. Stay organized, easily access what you need, and keep on trekking. Travel & Organization Our collection of travel and outdoor accessories features a wide range of must-haves for organized, adventures. Sea to Summit Reactor Sleeping Bag Liner Thermal boost liner retains heat, adds warmth to your sleep system in colder conditions, and acts as a hygienic layer to extend the life of your sleeping bag. Shop the Collection Reactor Bag Liner Comfort Blend Bag Liner Ether Light XT Pad Comfort Light Pad Pursuit Self-Inflating Boab Sleeping Bag Spark Pro Sleeping Bag About the Sea to Summit Reactor Sleeping Bag Liner Sea to Summit Reactor series insulated sleeping bag liners can extend the comfort range and improve personal hygiene of any sleeping bag. Thermolite hollow core fibers are constructed like the fur of a polar bear, efficiently trapping heat and providing a luxuriously soft, comfortable feel. The stretch-knit fabric provides optimal comfort, and ensures the Reactor fits any sleeping bag. Additionally, the drawcord footbox offers plenty of ventilation and the versatility of walking around camp while still wearing your liner. Available in three different weights, Reactor technical liners make your existing sleeping bag warmer and more versatile. The Regular Liner uses hollow-core Thermolite Pro fabric with infra red-absorbing ceramic pigments and Thermolite EcoMade fibers. This lightweight fabric adds up to 14F of warmth to your sleep system. The Extreme Liner features a thicker hollow-core Thermolite Pro fabric to add up to 25F of warmth to your sleep system. The Fleece Liner employs hollow-core Thermolite Pro fibers in a grid-pattern to deliver our warmest sleeping bag liner which adds up to 32F of warmth to your sleep system. Review: Warm and comfortable. - Kept me pretty warm with my 32F down sleeping bag in 25F weather. My feet got a little cold but wasn’t bad enough to keep me up all night. Review: It worked for me! - First night was in the 20’s f and worked great with my sleep system. I woke up to a small amount of snow and was warm without feeling drafts in my hammock. I use this every time in my sleep system ## Features - thermolite - Imported - Insulated sleeping bag liner adds extra warmth and personal hygiene to any sleeping bag. - Hollow-core Thermolite EcoMade fibers are used in a grid-pattern fleece for maximum warmth retention - Drawcord footbox can be opened or closed for optimal comfort and integrates perfectly with the footbox of our Free-Flow Zip system in select Sea to Summit sleeping bags - HeiQ Fresh odor control technology helps keep the liner fresh even after extended use - A mummy shape designed for maximum thermal efficiency including shoulder zippers and a footbox drawcord for additional temperature regulation, Sea to Summit Guarantee is offered for the Lifetime of this product ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0CT67SDHF | | Additional Features | Thermal Boost, HeiQ Fresh Odor Control, Drawcord Footbox | | Age Range Description | Adult | | Best Sellers Rank | #19,234 in Sports & Outdoors ( See Top 100 in Sports & Outdoors ) #12 in Camping Sleeping Bag Liners | | Brand | Sea to Summit | | Brand Name | Sea to Summit | | Closure Type | Drawstring | | Color | dark blue or black | | Customer Reviews | 4.7 out of 5 stars 272 Reviews | | EU Spare Part Availability Duration | 7 Years | | Fabric Type | thermolite | | Fill Material Type | Thermolite | | Global Trade Identification Number | 09327868158355 | | Item Dimensions L x W | 78"L x 31.5"W | | Item Weight | 0.92 Pounds | | Manufacturer | Sea to Summit | | Manufacturer Part Number | ASL031031-191902 | | Material | thermolite | | Maximum Height Recommendation | 85 Inches | | Model Number | ASL031031-191902 | | Occupancy | 1 | | Seasons | 3 Seasons | | Shape | Mummy | | ShellMaterial | thermolite | | Size | 78 inches x 31.5" | | Sport Type | Camping & Hiking, Backpacking, Hiking | | Temperature Rating | 32F and above | | Thermal Resistance | 32 | | Unit Count | 1.0 Count | ## Product Details - **Age Range (Description):** Adult - **Brand:** Sea to Summit - **Color:** blue - **Material:** thermolite - **Occupancy:** 1 - **Seasons:** 3 Seasons - **Shape:** Mummy - **Special Feature:** Thermal Boost, HeiQ Fresh Odor Control, Drawcord Footbox - **Sport:** Camping & Hiking, Backpacking, Hiking - **Temperature Rating:** 32F and above ## Images ![Reactor Insulated Sleeping Bag Liner - Image 1](https://m.media-amazon.com/images/I/51qPNmVP9UL.jpg) ![Reactor Insulated Sleeping Bag Liner - Image 2](https://m.media-amazon.com/images/I/814fEI0Y8kL.jpg) ![Reactor Insulated Sleeping Bag Liner - Image 3](https://m.media-amazon.com/images/I/71nM+r47v6L.jpg) ![Reactor Insulated Sleeping Bag Liner - Image 4](https://m.media-amazon.com/images/I/31A+1-F9VtL.jpg) ![Reactor Insulated Sleeping Bag Liner - Image 5](https://m.media-amazon.com/images/I/81dtfNHeOgL.jpg) ## Available Options This product comes in different **Style** options. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Warm and comfortable. *by J***K on February 10, 2026* Kept me pretty warm with my 32F down sleeping bag in 25F weather. My feet got a little cold but wasn’t bad enough to keep me up all night. ### ⭐⭐⭐⭐⭐ It worked for me! *by W***N on January 29, 2026* First night was in the 20’s f and worked great with my sleep system. I woke up to a small amount of snow and was warm without feeling drafts in my hammock. I use this every time in my sleep system ### ⭐⭐⭐⭐⭐ Great liner for summer months *by C***R on January 7, 2026* i’m not keeping this because I need something a little warmer. I’m getting ready to start the Appalachian Trail and I just don’t think this is warm enough for me looking for a warmer insulated liner for my sleeping bag. If I wouldn’t be hiking in the cold, I probably would’ve kept it. --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.uk/products/630870203-reactor-insulated-sleeping-bag-liner](https://www.desertcart.co.uk/products/630870203-reactor-insulated-sleeping-bag-liner) --- *Product available on Desertcart United Kingdom* *Store origin: GB* *Last updated: 2026-05-17*