BEST USE: Backpacking & Camping
WEIGHT: 14 oz | 399 g
LENGTH: 6 ft 10 in | 210 cm
PACKED SIZE: 6.5 x 4.5 in | 17 x 11.5 cm
Shipping & Returns
We use climate-neutral shipping with DHL GoGreen.
For orders with a value below 75€ we charge a shipping fee of 4,95€. We do not charge shipping fees for orders with a value over 75€.
All orders received by 12:00 noon on weekdays are usually shipped the same day. Later orders are usually dispatched the following working day.
Delivery time can take up to three working days Germany-wide and up to four working days for orders outside of Germany, and depends on the shipping service provider.
All orders can be returned within 14 days of purchase. However, for the sake of the environment, please make sure to keep returns as low as possible.
The THERMOLITE® Reactor Extreme liner is Sea to Summit’s warmest knitted sleeping bag liner. If your adventures take you to colder climates, the Reactor Extreme will add plenty of warmth to a sleeping bag. Plus in warmer weather, it can be used as a ‘stand alone’ sleeping bag. The hollow core fibres of the THERMOLITE® fabric work like a polar bear's fur and, along with the knitted structure, trap plenty of insulating air. Super soft and amazingly stretchy, the Reactor Extreme uses a heavier version of THERMOLITE® to provide extra warmth for an incredibly comfortable night’s sleep. Use one to build your cooler-weather sleep system and to help keep your sleeping bag clean too.
The Reactor Series Sleeping bag liners, the Venture, Traverse and Basecamp synthetic Sleeping Bags and the foot boxes of the Women’s Altitude and Journey down Sleeping Bags use hollow core THERMOLITE fiber to add warmth. These fibers trap extra air for insulation (just like the hollow-cores of polar bear or caribou fur). In the liners, the knitted THERMOLITE fabric is soft and stretchy and comes in three different weights: 80g/m² fabric used in the Reactor and the underside of the Compact Plus liners; a 110g/m² fabric which is used in the Extreme, and the core and foot box of the Compact Plus liner; and the Fleece, the warmest of all the fabrics. THERMOLITE is also used in the Air Sprung Cell sleeping mats.
Added WarmthUp to 25°F / 14°C
Best UseBackpacking, Camping & Winter Camping
Comes WithUltra-Sil stuff sack
Material(s)Thermolite polyester fabric
|Regular Mummy||Long Mummy|
Frequently Asked questions
Suitable for use with a rectangular / wide sleeping bag?
The knitted fabric of the Reactor is so stretchy that you won’t feel the shape of the liner at all.
Equipped with a zipper?
No - to keep this sleeping bag liners at a minimal weight and packed size we did not include a zipper.
Washed in a washing machine?
Yes - you can wash your liner in a washing machine with normal supermarket laundry ‘soap’ and dry it in a dryer, using cool or low heat. Fabric softeners will reduce wicking performance of the fabric.
You have more questions?
Check out our FAQ page HERE and discover even more answers about our products.