Complex sentence: Ugg boots (sometimes called uggs) are known in Australia and New Zealand as a unisex style of sheepskin boot made of twin-faced sheepskin with fleece on the inside and with a tanned outer surface, often with a synthetic sole.
Split into simpler sentences: Ugg boots (sometimes called uggs) are known in Australia and New Zealand as a unisex style of sheepskin boot. The boots are made of twin-faced sheepskin with fleece on the inside and with a tanned outer surface, often with a synthetic sole.