The 4D Sim Racing Shoe (SRS) and Reactions Gaming Shoe models are custom engineered to give drivers the best feel for the pedals in their Sim Racing Rigs. Other sim-racing shoes are no more than karting or auto racing shoes, which must meet stringent regulations for fire resistance and safety. In the Simulator, there is no risk of impact or fire, so why not eliminate the excess and get down to what matters the most – FEEL.