Natural Rubber also called India rubber or caoutchouc as initially produced consists of polymers of the organic compound isoprene with minor impurities of other organic compounds, plus water. It is the only non synthetic elastomer in wide use, a although some variations such as guayule continue to be researched for applications in tire and non-tire end uses. Derived from the milk-like liquid of the Hevea tree, natural rubber latex contains many organic and inorganic properties. It has a large stretch ration and high resilience and is extremely waterproof.