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Expander Travel Liner

Protect your sleeping bag from your end of day dirt

$29.95 – $49.95

Size Guide

Sleeping Bag Temperature Ratings Explained

The EN Rating scale is a scientific test to determine the warmth of a sleeping bag. The test produces a Lower rating (for male sleepers) and a Comfort rating (for female sleepers). Both are listed in the features table on the product page.

A unisex sleeping bag with a Lower limit of 14ºF means a man should be comfortable down to air temperatures of 14ºF. The same bag will also have a Comfort limit, in the realm of 27°F, so a woman would be comfortable down to an air temperature of 27ºF. These ratings require a sleeping mat with an R-Value appropriate for expected ground temperatures – without this, the sleeping bag itself is unlikely to keep the sleeper warm enough.

A variety of factors impact sleeping bag warmth - the above temperatures are merely guidelines, not guarantees. It’s important to think of a sleeping bag, an appropriately insulating sleeping pad and a liner as a sleep system. For example - if you plan on sleeping in nighttime air temperatures of 27ºF / -3°C, choose a bag with a gender-appropriate rating of 23°F / -5°C, plus a sleeping mat with an R-Value of 2.5 to 3, and consider a Reactor thermal liner.



The Expander™ sleeping bag liner is made of a super soft and stretchy knitted poly-cotton material. The Rectangular, Traveller and Double models do not have side seams, and combined with the stretch fabric, this offers an unprecedented level of comfot in a budget-priced liner. A built-in antimicrobial treatment keeps odors at bay and won't wash out of the liner when you throw it in the washing machine. This is the perfect travel companion for those looking for a luxuriously comfortable sleep.

Our blog post "Which Sleeping Bag Liner Should I Choose" has some helpful tips on picking the perfect liner

Technical Features


Sea to Summit uses an anti-microbial finish in two different applications.

The internal laminate of Sea to Summit Air Sprung Cell mats is treated with an anti-microbial compound to prevent mold (which could otherwise result from condensed breath moisture remaining in the mat for long periods)

The fabric of Expander liners has an anti-microbial finish to keep the knitted poly-cotton fabric fresh and odor free.

Both finishes are permanent.

Tech Specs

Product Details

Comes With
Storage case
Stretch knit cotton and polyester blend (35/65)
Anti-microbial protection
expander-travel-liner-mummy.svg expander-travel-liner-traveller-w-pillow-insert.svg expander-travel-liner-rectangular.svg expander-travel-liner-long-rectangular.svg expander-travel-liner-double.svg
6 ft 10 in x 36 in / 210 x 92 cm
6.5 x 3 x 5 in / 16.5 x 8 x 13 cm
12 oz / 340g
7 ft 1 in x 36 in / 225 x 92 cm
7 x 4 x 5 in / 18.5 x 9.5 x 13 cm
13.4 oz / 380g
6 ft 1 in x 36 in / 185 x 92 cm
6.5 x 3 x 5 in / 16.5 x 8 x 13 cm
11 oz / 310g
7ft x 1 in x 36 in / 208 x 91 cm
5 x 6.5 x 3.5 in / 12.7 x 16.5 x 7 cm
13.4 oz / 380g
6 ft 1 in x 73 in / 185 x 185 cm
7 x 5 x 4.5 in / 18.5 x 13 x 12 cm
21.9 oz / 620g


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