Designed to take on the steepest and most technical terrain you want to explore
The Hayatsuki GTX is perfect for hard mixed terrain at high altitudes up to 4,500 meters. Handcrafted by AKU in Montebelluna, Italy and designed with elite athletes in mind, the Hayatsuki is constructed with only the best materials available. The Hayatsuki boasts a rubber and Liba®Smart PU protective rand, toe and heel welts for crampons, a lining with Primaloft® eGore-Tex® for thermo regulation, a heat sealed exoskeleton, micro pulleys, an adaptive lace-lock system and a double density exoskeleton midsole.
GORE-TEX Insulated Comfort + PrimaLoft
Keep your feet warm dry in all mountain conditions with the integrated waterproof GORE-TEX Insulated Comfort+ membrane. With added Primaloft insulation, you will be sure to stay warm.
The VIBRAM Curcuma mountain sole is crampon compatible and designed to carry you through any terrain. From rugged trails to steep snow and ice, it is there for you.
Elica Natural Stride System
Our Elica Natural Stride System ensures an anatomical fit to provide better stability and weight distribution across your boot sole to reduce pressure points and encourage better form and performance.
- Lining Description: Waterproof GORE-TEX® Insulated Comfort + PRIMALOFT
- Sole: Vibram Curcuma Mountain Sole
- Footbed: AKU Custom Fit Insole with Aluminum Insulaton
- Lasting board (stiffness): 6-4 MM GLASS FIBRE + DIE CUT EVA (Fully Rigid)
- Midsole: Double Density Polyurethane Exockeleton
- Upper: 3.0MM Italian Perwanger Leather + Elastic Textile + AIR8000®
- Upper protection: Rubber Rand +LIBA®SMART PU
- Crampons: Step-In, Strap-On, Hybrid
- Resolable: Yes
- Weight: 914 Grams per Boot
- Handcrafted by AKU in Italy
I wear a UK 10, 4E / EU 45 pair of Brooks Running Shoes. The AKU 46.5 is perfect for me considering I'll be using it at very high altitude. It is reasonably warm, and sufficiently waterproof. Layer up socks accordingly for colder temps.
AKU is perhaps the only boot which doesn't squeeze my toes. Which is probably the most important factor to protect against frost bite.
I would love to see a double boot from AKU for -40 to -50 ° C. I will surely buy it.
Overall I am extremely satisfied.
I have a slightly wide feet compared to it's length which make it sometimes challenging to find a right fit. those boots are super confortable right out the box and fitted around my feet shape and ankle way better than other iconic mountaineering boots brand.
So far I have been using them mostly while ice climbing.
I usually wear a 10.5 for trail running and hiking shoes, I choose a 11 and I have not suffered any toes injury from hitting ice wall. My feet and ankle feels snug and well maintained yet not restricting bloodflow and I can move around my toes individually if needed.
My feet have stayed warm while being outside all day at -20C while alterning between static and active phases.
The lacing system is extremely convenient, enabling you to dial the tightness independently between the ankle and the feet.
Patricia from customer service was very helpful in answering my question about the product.
The only downside I found so far, it that they tend to loosen up a bit as the day goes. This might get better the more they break-in thought. I also wished they were a tad lighter (2080 gr/pair Size 11)
Love the fit, design, and (so far) durability.
Def the easiest break in period I've had with boots of this style as well. High quality, good fit.