The Alpinist. Center Zip Mummy Bag in 35° or 20°

New product

The Alpinist is Nunatak's ultralight mummy sleeping bag.

More details


Add to wishlist

Pay via Credit Card or Paypal Account
Pay via Credit Card or Paypal Account

With the Alpinist we sought to rework the traditional mummy into a sleeping bag we feel is more useful.

We moved the zipper from the side to a center front location. This gives you full use of both arms while still having head and back snug in the sleeping bag, a must when performing sitting camp tasks in less than ideal conditions.

This unique center zip provides more effective torso ventilation, but can also seal up very effectively via the double draft tube backing.

When side sleeping the zipper typically ends up slightly in front, down from the shoulder a bit. Whether it is open for venting or snugged up, this is an ideal location. From here the zipper is conveniently controlled without contortions, and the dreaded back side cold spot from traditional zipper placement on the side hem, is completely eliminated. In fact, side sleeping is almost where the center zip placement is at its best.

Remaking the traditional head opening into the Alpinist/Raku style hood is the natural follow-up to the zipper relocation and is very effective at keeping you warm with less material. When using the Alpinist in warmer conditions, pulling out the head and shoulders from the hood and lying on top is simple. It is easy to do a non-shifting pillow arrangement inside the hood.

The 20° Alpinist is built with a 2" differential cut, a feature that greatly increases the efficiency of a given fill volume.

A Multitude of Stock Options

The Nunatak Alpinist is likely one of the more customizable mummy bags on the market. Using the many options in the configuration menu below, one can create the perfect fit either for body size, special applications or desires. 


We offer 4 overall lengths, from small to extra long. 

3 different shoulder width options with corresponding increases in interior volume. The size choices carry on into the hood and hip area: for example an extra wide bag will also have a bigger hood and a roomier lower middle section. The standard 30" width is well sized for most individuals. If your desire is an extra roomy feel, choose 35", and for the very few needing the outmost in sprawl there's a 40" option. Be aware that a large interior volume requires a more energy to keep warm. 

The footbox circumference can also be individually sized, independent of length and width. Here the standard is the 38" circumference. For folks with small feet a 34" footbox will be warmer, and, off course, the big guys might consider the 42".

If your needs are not met by the easily configured options presented in the menu below, we also have unlimited custom adjustments available. Please call or email.

Shell Material

For the Alpinist we have literally a staggering amount of shell fabric choices. Please consult the Fabric Info page for detailed description. Basically there's 3 distinct groups:

*The UL (UltraLight) shells in 0.66 and 0.8 ounces per square yard.

*The standard shells in 1.0 oz/yd, plus a couple of nice camo fabrics and the venerable Epic.

*The two advanced waterproof/breathable options, one a super light 0.74oz/yd, the other a membrane laminate similar to Goretex, at 1.4 oz/yd . Take note that a significant increase in final cost is associated with these.

Temperature Rating 35° or 20°
Baffle height 1.25 or 2.25
Insulation Loft 1.5 or 2.5
Fits to Height Small: 5' 4"....Medium: 5' 10"....Long: 6' 3" ....XLong: 6' 8"
Shoulder width options 30" - 35" - 40"
Foot Area Circumference 34" - 38" - 42"
Differentially cut liner/shell 20° - 2"
Zipper 28", 38" or 48" YKK Coil.
Fill Volume, 20°F, Long x 30" W x 38" Foot 18,3 oz
Fill Volume, 20°F, Long x 35" W x 38" Foot 20.3 oz
Fill Volume, 20°F, Long x 40" W x 38" Foot 23.8 oz
35°F, Long - 30" W - Total Weight, 0.66 Membrane Shell/Liner 21.5 oz
35°F, Long - 35" W - Total Weight, 0.66 Membrane Shell/Liner 23.2 oz
35°F, Long - 40" W - Total Weight, 0.66 Membrane Shell/Liner 25.6 oz
20°F, Long - 30" W - Total Weight, 0.66 Membrane Shell/Liner 26.8 oz
20°F, Long - 35" W - Total Weight, 0.66 Membrane Shell/Liner 29.9 oz
20°F, Long - 40" W - Total Weight, 0.66 Membrane Shell/Liner 33.5 oz

Write a review

The Alpinist. Center Zip Mummy Bag in 35° or 20°

The Alpinist. Center Zip Mummy Bag in 35° or 20°

The Alpinist is Nunatak's ultralight mummy sleeping bag.

Product Options
Temperature Rating
The 20° is a solid 3 season sleeping bag.
Shoulder Width
The standard works for most.
Zipper Length
38" and 48" zippers are YKK #5 two-way inside/out coil.
The 28" option is an ultralight one way #3 coil.
Foot Box Circumference
Shell Fabric

Please go to the Fabric Page for help choosing the shell material.

Liner Fabric
Down Type

Choosing Hyper-Dry moisture resistant down will help combat the effects of perspiration, misting tents and damp air. Nunatak products made with Hyper-Dry down will have a slight increase in bulk over those made with regular down. In some instances they may contain an additional 5% of fill weight.

900 Fill Power Goose Down, RDS Certified
900 Fill Power Hyper-Dry, RDS Certified
Down Overfill
Cold sleeper? Consider adding a few ounces of extra fluff.