Authentic Mens UGG Boot is part of the popular Ugg boots (sometimes called uggs),they are a unisex style of sheepskin boots, made of twin-faced sheepskin with fleece on the inside and with a tanned outer surface, often with a synthetic sole.Originating in Australia or New Zealand, where they became popular in the 1970s,New Ugg Boots Outlet emerged as a fashion trend in the United States in the late 1990s and as a world-wide trend in the late 2000s.