Men's Mountaineering Boots Product Information
The size tag reads 44.5, USM 11, UK 10. I used these boots on Aconcagua and loved the hard rubber sole and removable liner. I wear a 10 in most shoes. I sized up for these boots to wear a thin liner sock with an expedition weight wool sock. My feet had plenty of room at elevation without any heel lift. My toes also didn't hit on the way down.
These boots are probably (definitely) overkill for most adventures unless you get cold feet quickly. I'm only selling because my bank account is pretty low after my trip to South America.
La Sportiva Baruntse Mountaineering Boots