Akula APEX Half Bag.

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A waist high synthetic filled sleeping bag to be used with the Skaha APEX Hoodie as a complete sleep system. 

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Full weight chart up soon.

For more than half a century the climbers of the European Alps have embraced this concept for one or two night forays into the hills. Nunatak has given new life to idea of the historic 'Elephant's Foot' with the Akula. 

For this modern rendition we use Climashield APEX insulation in three levels and a selection of super ultralight high tech fabrics.

Skaha Apex Hoodie, available here, and the Akula Apex half bag, both with Climashield synthetic insulation and an ultralight waterproof/breathable shell material, offers a supremely weather resistant bivy set up good to 40°.

At just 530g (18.7oz) combined for the jacket and half bag in size large, this fully customizable suite is surprisingly compact, versatile and reasonably priced, starting at $400 depending on sizing and options. Order the half bag on this page, the Skaha APEX pullover over here

The Apex insulation in the pictured setup above is the 2.5 oz/yd. Combined with other layers it should be good to 40° for brief stops, naps, recovery breaks. For a full night at those temperatures up the insulation to 3.6 oz/yd or 5.0 oz/yd.

Several shell and liner materials are available.

With the ultralight 0.74 oz/yd waterproof/breathable shell material AND the synthetic insulation there would be no degradation of the R-value due to dew, mist and body moisture. Even in light rain, with a little shelter from boulders or vegetation, one should be fine for several hours.

Typical users would be packrafters, bikepacking racers, folks doing FKT attempts, or any trip in mild, moist conditions, such as the west coast of Canada/Alaska.

For sizing of the Akula APEX half bag there's 4 choices in length and two footbox sizes, besides the full suite of Nunatak technical fabrics.

Bivy Extension

This is an extended single layer fabric 'sleeve' permanently attached to the top edge of the insulated part. Long enough to cover one's head with a scalloped cut that makes the front lower than the back. Two drawstrings: one at the top of the half bag, operated from the inside, and another controlling the top opening of the sleeve. See pics below.

The back side of the single layer top  is 36" tall, the lower front side is 18" tall, and weight is 65g in all sizes.

Use the example on the right as guide line for measuring yourself and determining which length to select for lower insulated bag.

After saving your customized product, remember to add it to your cart.



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Sweet piece of gear!

Thank you Nunatak! Had great results with this bag customized with a shock cord opening at the foot and waist draw cord. Called it the tube, a great multi purpose piece of gear in cold and wet conditions. Used as camp wear, added insulation/protection to down sleeping bag, and can be pulled out for warmth (as skirt or stiffed down pants or jackets) while on the go without compromising sleeping bag. Can't comment on the stability/longevity of the insulation, only used on 2 trips.

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Akula APEX Half Bag.

Akula APEX Half Bag.

A waist high synthetic filled sleeping bag to be used with the Skaha APEX Hoodie as a complete sleep system. 

Product Options
Temperature Rating
Rating reflects insulated half bag paired with an appropriate parka.
Half Bag Length

The length/user height should allow for adequate low back coverage in sitting position. If in doubt size up and/or perform some measuring before ordering.

Footbox Size
The 38" footbox fit most normal sized feet without footwear.
Top End Closure
Eliminating the top end closure saves 14 grams, but is really only useful if the Half Bag is tucked UNDER the parka.
Shell Fabric

Typically listed from lightest to most durable. Please go to the Fabric Page for help choosing the shell material.

Liner Fabric
10d Black Taffeta - Lightest, most breathable
20d Black Taffeta - Durable
Extension Single Layer Bivy Sleeve
Un-insulated bivy extension is always matching Akula shell material. Adds about 50 grams.
Roomy to allow for simple tasks inside sleeve; top closure for sleeping draft free; and, with the 7d Robic shell, keeping you dry in situations with heavy dew, mist, light spray. Not seam taped.
Your Measurements
Optional: Fill in the blanks to ensure getting the best fit. No changes will be made to your size selections without approval
Shoe Size 
Stuff Sack
Our stuff sacks are pretty dope, but current weight saving trends in ultralight circles eschews this once crucial item. So, opt out and save $ while also being very current.