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Aku Aurai DFS GTX Review

Aku Aurai DFS GTX
  • Comfort
  • Protection and support
  • Traction and grip
  • Performance on rock
  • Performance on snow/ice
  • Thermal comfort
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Boot created for high altitude and ice falls, which is not afraid of long approaches and challenging routes. Perfect for summer high altitude where you will greatly appreciate the comfort in walking and precision, both with crampons and without. Can go into difficulty in very cold temperatures. Also available in women’s version.


  • Soft,wrap-around upper
  • Comfort in walking
  • Precision on technical terrain
  • Versatile and effective lacing


  • Cold insole at low temperatures

Aku Aurai DFS GTX: the most important features of this boot are condensed in this name.

Aurai: this is the ancient name of the Lagorai mountain range. A special massif at the edge of the dolomites, of volcanic origin, wild and closed. All to be explored.

DFS is Aku’s proprietary double lacing system. GTX on the other hand stands for Gore-Tex.

So already from the name we know we have a boot developed with cutting-edge technologies, made for those who want to explore their limits.

aku aurai dfs on test

Technical features of the Aku Aurai DFS GTX

  • High altitude and ice climbing boot
  • Integrated elastic and Kevlar-reinforced Kevlar gaiter closed with zipper
  • Gore-Tex insulated comfort and primaloft lining
  • DFS: dual fit system. Dual internal lace-up closure
  • Carbon and aluminum honeycomb mounting footbed
  • Aole: Vibram® croda litebase
  • Weight: 700 g
  • Manufacturer link

The Aku Aurai DFS GTX are presented as modern high altitude boots: thermal and waterproof upper with lace-up closure and protected by an integrated gaiter closed by a soft longitudinal zipper.

aku boot

The construction is the classic one with a mounting insole.

The upper is a single body that is glued around the mounting insole, under which the sole and crampon mounting hardware is then glued.

The mounting footbed is made of carbon to increase rigidity without adding weight, a standard for this type of boot. Aku on this traditional mounting has brought the innovation of the Helix system: in this construction system, the shape around which the boot is built imposes on the mounting insole, midsole and tread the anatomical shape of the foot.

aku aurai dfs on rock

The weight of 700 g in size 43 is right and in line with the type of construction adopted.

Test mode

I tested these boots on snow walks in February 2023 and on some nice icefalls in the Dolomites area. In June I was then able to use them in high altitude.

approaching incefalls

Aku Aurai DFS GTX on-site test

The Aku Aurai DFS GTX as soon as you open the package immediately appear to be “contained” boots. What will in fact please many is their low volume; to me they immediately gave an impression of precision. Wearing them is very easy both at the generous opening of the laces and the soft gaiter.

Double lacing

Right from the start what immediately impresses is the double lacing DFS – Dual Fit System, typical of many Aku models. In technical high altitude and icefall boots we have two phases of boot use:

  • Approach: in this phase the lacing is by all kept comfortable to have better flexibility of the upper and more thermal comfort, because the foot is not compressed and the blood is free to circulate.
  • Climbing: in this phase, on the other hand, it is important to have the boot tightly closed for maximum precision.
Detail of the DFS lacing system
Detail of the DFS lacing system

With the DFS system, on the other hand, we have a double line of laces: the lower one is closed as usual with a knot and is adjusted for walking – Aku calls it Comfort Walk.

The upper line of laces is white tubular rope with an automatic lock and only covers the foot. To tighten it, simply pull the white rope and choke it. This can be done with gloves on. This way you never loosen the base laces and tighten the boots quickly when needed. This is the closure called Precise Climbing: simple and ingenious.

Lacing system detail
Lacing system detail


Another nice surprise about this boot that sets it apart greatly from others of the competition is the softness of the upper. When you slip your feet in and close the laces you feel a soft upper wrap around your feet, without creating acute pressure anywhere on the foot.

This result is made possible by both the choice of materials and their bonding, which avoids stiff points. At the bottom of the boot, the Spider Frame superstructure gives just the right amount of give, without lacking support and protection thanks to the Kevlar fabric that runs around the boot.

Upper detail with Kevlar and Spider Frame
Upper detail with Kevlar and Spider Frame

This translates into action in a comfortable boot that you walk well in.

With these boots I did an eternal approach this January along the Vallunga of Val Gardena. I had no pain at all on my first ever use of these boots. This June, on the other hand, I tackled the Carrè Alto and still a long descent of 2000 m did not bother me at all.

walking with aku boots

This softness is also helped by the zipper closure, which is yielding just right.

Thermal comfort

The thermal insulation of these boots is provided at the upper level by the Gore-Tex Insulated Comfort lining.

Primaloft inserts are added on the toe (without making it bulky anyway) and on the front tongue. At the insole level, however, insulation is achieved only by a felt footbed and aluminum honeycomb sheet.

In the end, the result is a warm but not super warm boot.

During ice falls this winter I was fine while climbing, experiencing a few devils in my feet while at belay. This June, on the other hand, the boot has been perfect for temperatures around freezing, both on rock and immersed in snow.

aku aurai dfs on snow

Thanks to Gore-Tex we still have a boot that is breathable and has good protection from water ingress.


The Elica system, as mentioned above, determines the shape of the boot under our feet and the position of the cushioning inserts on the heel and toe. The result is a consistently comfortable and ergonomic roll. This is not taken for granted by having a rigid carbon insole that must also support the foot well in crampon use.

elica system

The Vibram Croda Litebase sole is lightweight and precise on both rock and snow. The boot is also resoleable.

vibral sole detail
Vibram Croda Litebase
sole detail


As mentioned, the carbon footbed creates a rigid platform for the automatic crampons. In action the boot immediately succeeds in making the toe load feel good on both ice and rock. Missing at the end of the zipper is a trouser gaiter attachment point, which would be useful especially when using fully automatic crampons.

aku aurai dfs on ice
aku boots with crampons


I generally use 43.5 as my shoes. According to Aku’s size guide for a 27.8 cm long foot I should get the 43. So I did and the boot in this way immediately felt very precise. I must say I have a normal footbed, not too wide.

Compared to the Zamberlan Zarathustra I would say the Aku Aurai has a slightly narrower footbed. This will be of interest to those who often find that hiking boots have wide footbeds, especially the female audience. I will point out that there is however also a women’s version of this boot.

I generally always use thin socks even in very cold weather. I prefer to have a lightweight sock that dries quickly, rather than one that is warm but struggles to dry.

For those who prefer thicker socks or more room at the toe I recommend compared to Aku’s size guide to go up half a size.

aku on rock

Recommended for

The Aku Aurai DFS GTX walk great and are light and accurate both on rock and mounted with crampons. I consider them to be the best choice for those who want to do summer mountaineering at high altitudes, from Mont Blanc to all the 4,000-meter peaks of the Alps.

In very technical uses on icefalls or winter mixed climbing, however, I think they can be a bit cold.

Note the availability of the women’s version as well.

Value for money.

Price: € 529.90

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