UGG Sienna Matte Women's Rain Boots in black are made of rubber, with a mid-calf shaft style and a round toe shape. They have a pull-on closure and a flat heel height. These boots are available in size 6 for UK, US, and EU shoe sizes, with a medium shoe width. The outsole and upper material are both made of rubber, as well as the insole. The boots are designed for women and are part of the UGG brand. , ,t