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UltraLight Self-Inflating Sleeping Mat

Lightweight, simple & sturdy

$89.00 – $119.00

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.



For the ultralight enthusiast, the Ultralight™ Self Inflating mat will add the promise of comfortable sleep to your pack, without a lot of weight or bulk. Delta Core-V™ technology is used to remove small sections of foam without sacrificing comfort. The silicone grip print embossed on the mat ensures you and your sleeping bag stay on the mat. For the ultralight adventurer, pack up is super easy with the patent-pending multi-function valve that allows you to roll up the mat without air trying to sneak back in as you go. Ideal for gram counters who like to sleep comfortably.

Our blog post "Which Mat Should I Choose" has some helpful tips on picking the perfect air mat (or reasons why you might prefer a Self-Inflating mat).

Technical Features

Delta Core-V­™

In our lighter SI air mat models, we have removed 20% of the weight and bulk of the PU foam by using our vertical Delta Core-V™ method. We use sophisticated pressure mapping data that becomes the blueprint for our distinctive graduated core pattern.

Where extra warmth and support is needed for the body contact areas - shoulders, hips, and feet - the core holes are smaller. In the less critical areas, we have removed more foam to minimize the weight and packed size. Delta Core-V™ technology is used in our Ultra Light SI and Camp Mat SI models.

SI Multi-Function Valve

We have literally put a new twist on our very successful multi-function valve so it specifically addresses the inherent characteristic of self-inflating mats - that is, the problem of the foam trying to re-inflate as you're packing up. We've engineered the "one-way" inflation valve to be reversed and used to prevent the mat from drawing air back in. This allows you to roll the mat up as small as possible without fighting re-inflation as you go. This patent-pending valve design has the same slim profile, faster inflation than traditional screw valves, easy pressure fine tuning, and super fast deflation rate as our air mattresses and pillows.

Extrusion Lamination

Extrusion lamination is common in the medical and aeronautical industries, but Sea to Summit pioneered its use in outdoor products. Liquid Thermoplastic Urethane is applied to the face fabric through an extrusion head, where it bonds permanently. The result: Sea to Summit sleeping mats are more reliable and longer-lasting.

Pillow Lock™ System

The Pillow Lock™ System comprises of self-adhesive hook-and-loop patches which are supplied with all Sea to Summit sleeping mats (as of Spring 2019),

Attached to your sleeping mat, these patches secure your pillow and prevent it slipping – yet they will not snag on clothing or other lightweight fabrics.

All Sea to Summit Pillows (as of Spring 2019) are compatible with this system. Existing pillows can be made Pillow Lock™ compatible by adding an Aeros Pillow Case.

Tech Specs

Product Details

Best Use
Ultralight Backpacking, Camping
Comes With
Stuff Sack
30D Polyester with an anti-slip print
Delta Core-V technology
Season Rating
Summer and later spring / early fall
Multi-function valve that prevents re-inflation as you pack up
1 in / 2.5 cm
ultralight-self-inflating-sleeping-mat-x-small.svg ultralight-self-inflating-sleeping-mat-small.svg ultralight-self-inflating-sleeping-mat-regular.svg ultralight-self-inflating-sleeping-mat-large.svg
49 in x 20 in / 125 x 51 cm
4.25 x 11 in / 11 x 28 cm
1 in / 2.5 cm
13.9 oz / 395 g
67 in x 20 in / 170 x 51 cm
4.75 x 11 in / 12 x 28 cm
1 in / 2.5 cm
1 lb 2 oz / 520 g
72 in x 20 in / 183 x 51 cm
5 x 11 in / 13 x 28 cm
1 in / 2.5 cm
1 lb 3 oz / 550 g
78 in x 25 in / 198 x 64 cm
5 x 13.5 in / 13 x 34 cm
1 in / 2.5 cm
1 lb 9 oz / 720 g


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