PLEASE READ: these are Ugg boots I got from a company in Australia, not the Ugg brand boots sold by Deckers Footwear, the US company that manufactures the branded variety. They are genuine sheepskin and wool lining, which means they are really warm like the Ugg brand used to be. See photos for more info and feel free to ask me any questions. I am a US 6.5-7 (foot measures exactly 23.5cm when standing with heel against wall), and I find these run big. I sized down to a 6 in these boots so I recommend measuring your own foot and making sure these would be the right size for you!