Ilse Jacobsen Black Short Wellies RUB30C 001. Entirely PVC-free, our rain boots contain no animal by-products. The result is a sturdy and reliable companion for rainy days. They have a special anti-ice sole with a rough surface, providing the best possible traction in slippery and icy conditions. Handmade Chelsea ankle rubber boots. These Wellingtons are made of the finest single-estate natural rubber which is harvested sustainably. This rubber is mixed with our own secret recipe, making the fundamental composition 52% natural rubber and 48% secret recipe. Entirely PVC-free, our rain boots contain no animal by-products. The result is a sturdy and reliable companion for rainy days. We have developed a special anti-ice sole with a rough surface, providing the best possible traction in slippery and icy conditions. These Wellies withstands temperatures down to -20 degrees Celsius. Natural rubber will eventually develop a white surface over the years if you do not treat it regularly. This is simply because the rubber loses its essential oil. To keep your boots in great condition for many years to come, we recommend that you treat them with our oil once a month.