I bought a pair to try out in the Pamirs this summer up to 7000 meters.
I have not used them yet and cannot find any info on line. They look very well made and comparable to the other Everest grade boots out there. Although slightly heavier then some. That being said I expect them hold up a longer as well.
They run big. I usualy wear a 11.5 to a 12 and the 11.5 i ordered was huge even with 2 socks
This review was written in the old system and had content requirements that are different than reviews written today.