Koolaburra Rock & Roll Skulls authentic Australian Ugg boot features sheepskin upper, replaceable sheepskin insoles, form fitting foam footbeds, comfortable EVA sole, and the shaft is decorated with kettle black designs. Rock & Roll Skulls is available in black. Koolaburra Rock & Roll Skulls is a authentic Australian Merino Sheepskin boot with the stylish kettle black design pick your words and make a statement.