These are made from a high quality 100% natural Australian Merino sheepskin, and features double stitching, reinforced heel counter, and has the high-density Eva sole for long-lasting, durable wear, and removable innersoles. Sometimes the natural Merino sheepskins may have a natural flaw/colour change which does not come out during the tanning process. This is the sheepskin used to make the classic Ugg “Opal” Tidal 3/4 boot.