Rubber rings made of natural rubber. Stretchable, tension-resistant, and reusable. Diameter: 40 mm. Color: Red. Content: 50 g. Natural rubber is a rubber product that is produced without petroleum. It is primarily obtained by tapping the bark of the rubber tree. The latex, or plant milk, that flows out is collected and then acidified with acetic acid. Natural rubber is characterized by high elasticity and durability. It is water-repellent and is sustainably cultivated in mixed cultures.