---
product_id: 666660107
title: "Sea to Summit Reactor Sleeping Bag Liner, Extreme Standard (85 x 31.5)"
brand: "sea to summit"
price: "VT44537"
currency: VUV
in_stock: true
reviews_count: 5
category: "Sea To Summit"
url: https://www.desertcart.vu/products/666660107-sea-to-summit-reactor-sleeping-bag-liner-extreme-standard-85
store_origin: VU
region: Vanuatu
---

# Up to +25°F warmth boost Stretch-knit Thermolite Pro fabric Adjustable drawcord footbox Sea to Summit Reactor Sleeping Bag Liner, Extreme Standard (85 x 31.5)

**Brand:** sea to summit
**Price:** VT44537
**Availability:** ✅ In Stock

## Summary

> 🔥 Sleep warmer, move freer, stay fresher — your ultimate camp upgrade!

## Quick Answers

- **What is this?** Sea to Summit Reactor Sleeping Bag Liner, Extreme Standard (85 x 31.5) by sea to summit
- **How much does it cost?** VT44537 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.vu](https://www.desertcart.vu/products/666660107-sea-to-summit-reactor-sleeping-bag-liner-extreme-standard-85)

## 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

- • **Stretch-Knit Freedom:** Experience unrestricted movement with a mummy-shaped liner that flexes with you.
- • **Odor-Control Freshness:** HeiQ Fresh technology keeps your liner smelling clean, even after extended use.
- • **Thermolite Pro Warmth Boost:** Add up to 25°F of cozy heat to your sleep system, perfect for chilly nights.
- • **Versatile Footbox Ventilation:** Drawcord footbox opens for breathability or closed for snug warmth, plus easy camp mobility.
- • **Lifetime Sea to Summit Guarantee:** Invest in durability with a product backed for life, built for the adventurous professional.

## Overview

The Sea to Summit Reactor Sleeping Bag Liner Extreme Standard (85 x 31.5) uses advanced Thermolite Pro hollow-core fibers with infrared ceramic pigments to reflect body heat, adding up to 25°F of warmth. Its stretch-knit fabric ensures a perfect fit and freedom of movement, while the adjustable drawcord footbox offers customizable ventilation and mobility. Enhanced with HeiQ Fresh odor control, this mummy-shaped liner is designed for all-season use and backed by a lifetime guarantee, making it an essential upgrade for any serious outdoor enthusiast.

## Description

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: Very effective sleeping bag liner, warm and cosy - I used this to increase warmth in my 3 season nemo sleeping bag, it’s lightweight, thin fleece which yiu don’t expect to make much difference. However it’s amazing, excellent, warmed up straight away, it’s soft , cosy against your skin and makes the sleeping inside my sleeping bag a totally cosy , lovely experience. It’s pricey, but worth it.
Review: Fait d’un matériel assez mince - Camping d’automne Je m’attendais à ce que cela soit plus épais… Par contre je me suis sentie bien au chaud quand même.

## Features

- Insulated sleeping bag liner adds extra warmth and personal hygiene to any sleeping bag.
- Thermolite Pro technology using knitted, hollow-core fibers and absorbing infrared ceramic pigments to reflect your body's heat back to the wearer for enhanced warmth and comfort
- 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
- Knitted fabric provides incredible stretch and freedom of movement in this mummy-shaped liner and works seamlessly with sleeping bags of any shape, Sea to Summit Guarantee is offered for the Lifetime of this product

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0CT69SWJP |
| Age Range Description | Adult |
| Best Sellers Rank | #100,900 in Sports, Fitness & Outdoors ( See Top 100 in Sports, Fitness & Outdoors ) #10 in Sleeping Bag Liners |
| Brand | Sea to Summit |
| Brand Name | Sea to Summit |
| Closure Type | Drawstring |
| Colour | Orange |
| Customer Reviews | 4.6 out of 5 stars 357 Reviews |
| Fabric Type | thermolite |
| Fill Material Type | Thermolite |
| Global Trade Identification Number | 09327868158331 |
| Item Shape | Mummy |
| Item Weight | 0.38 Kilograms |
| Manufacturer | Sea to Summit |
| Manufacturer Part Number | ASL031071-190804 |
| Material | thermolite |
| Model Number | ASL031071-190804 |
| Occupancy | 1 |
| Outer Material Type | thermolite |
| Season | All Seasons |
| Seasons | All Seasons |
| Shape | Mummy |
| Size | 85 x 31.5 |
| Temperature Rating | 6 to 15 degrees Celsius |

## Product Details

- **Brand:** Sea to Summit
- **Colour:** Orange
- **Occupancy:** 1
- **Shape:** Mummy
- **Seasons:** All Seasons

## Images

![Sea to Summit Reactor Sleeping Bag Liner, Extreme Standard (85 x 31.5) - Image 1](https://m.media-amazon.com/images/I/51y1ZEIIHRL.jpg)
![Sea to Summit Reactor Sleeping Bag Liner, Extreme Standard (85 x 31.5) - Image 2](https://m.media-amazon.com/images/I/717FGa+RshL.jpg)
![Sea to Summit Reactor Sleeping Bag Liner, Extreme Standard (85 x 31.5) - Image 3](https://m.media-amazon.com/images/I/7142moFOpHL.jpg)
![Sea to Summit Reactor Sleeping Bag Liner, Extreme Standard (85 x 31.5) - Image 4](https://m.media-amazon.com/images/I/81XnJwN4QUL.jpg)
![Sea to Summit Reactor Sleeping Bag Liner, Extreme Standard (85 x 31.5) - Image 5](https://m.media-amazon.com/images/I/818yJJioawL.jpg)

## Available Options

This product comes in different **Style** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Very effective sleeping bag liner, warm and cosy
*by A***A on 10 January 2026*

I used this to increase warmth in my 3 season nemo sleeping bag, it’s lightweight, thin fleece which yiu don’t expect to make much difference. However it’s amazing, excellent, warmed up straight away, it’s soft , cosy against your skin and makes the sleeping inside my sleeping bag a totally cosy , lovely experience. It’s pricey, but worth it.

### ⭐⭐⭐⭐ Fait d’un matériel assez mince
*by A***R on 5 October 2024*

Camping d’automne Je m’attendais à ce que cela soit plus épais… Par contre je me suis sentie bien au chaud quand même.

### ⭐⭐⭐⭐⭐ Warm and comfortable.
*by J***K on 10 February 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.

## Frequently Bought Together

- Sea to Summit Reactor Insulated Sleeping Bag Liner
- Sea to Summit Drylite Towel, Lightweight Camping and Travel Towel
- Rainleaf Microfiber Towel Perfect Travel & Gym & Camping Towel. Quick Dry - Super Absorbent - Ultra Compact - Lightweight. Suitable for Trip, Beach, Shower, Backpacking, Pool

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**Shop now:** [https://www.desertcart.vu/products/666660107-sea-to-summit-reactor-sleeping-bag-liner-extreme-standard-85](https://www.desertcart.vu/products/666660107-sea-to-summit-reactor-sleeping-bag-liner-extreme-standard-85)

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*Product available on Desertcart Vanuatu*
*Store origin: VU*
*Last updated: 2026-06-05*