What is RSS 3 rubber?

Could you elaborate on the term "RSS 3 rubber"? It seems to be a niche concept that may not be widely understood. Could you break down its significance in the industry? What makes it unique or different from other types of rubber? How is it utilized in specific applications? Is it a recent development or has it been around for some time? Understanding its properties and uses would be invaluable for those seeking to gain a deeper insight into the materials science and engineering fields.