The Boreal Siula is perhaps the most versatile high altitude boot available. Warm enough for the coldest alpine conditions and tough enough for multi season use, Siula is the ideal choice for alps in winter and 7000m summit bids. Siula is a triple layer boot with an integrated outer gaiter, mid layer 'shell' and a removable inner bootie. The fully integrated outer gaiter keeps the elements out and is neatly and simply closed with a single premium quality water resistant zipper. The gaiter is reinforced with an extremely rip resistant material in the high wear zones and the new synthetic rand material is lighter and warmer than rubber and won't perish in the high U.V light conditions found at high altitude.