The 3.2 mm one-piece silicone impregnated leather upper offers excellent durability and fit for this winter mountaineering beast of a boot. The Nepal last offers an excellent fit for any foot and is easily adjustable with the removable/adjustable tongue. EZ Roller hardware allows you to lock down the laces and the Gore-Tex® lining provides long lasting warmth in the mountains. This boot is excellent for colder days where you need lots of support and protection on technical long endeavors. The best leather mountaineering boot on the market