Blue Soft Rubber (RC) WHEELS - The blue tire (tread) on this wheel is a flexible elastomer. What makes this elastomer special is its ability to bounce. Resilience in a wheel material is a necessary feature in order to protect the cargo being moved. The tire on this wheel is a resilient synthetic elastic rubber. It provides the performance of a cushion ride without the expense associated with a tire made using natural rubber. The tire is chemically bonded to a heavy duty impact resistant industrial grade polyolefin core (center).