3d printed in Grey
Size: 11.5 x 23 mm
The first rubber plant in Europe SK-1 (from Russian "Synthetic Kauchuk", Russian: ??-1) was established (Russia) by Sergei Lebedev in Yaroslavl under Joseph Stalin's first five-year plan on July 7, 1932.
In 1935, German chemists synthesized the first of a series of synthetic rubbers known as Buna rubbers. These were copolymers, meaning the polymers were made up from two monomers in alternating sequence. Other brands included Koroseal, which Waldo Semon developed in 1935, and Sovprene, which Russian researchers created in 1940
(more on Wiki HERE)