Pro Racer Rms. Carbon fiber backrest SUPREME PERFORMANCE SEAT The SP-X Avant has undergone repeated development tests on the Nürburgring and has been refined to exhibit excellent rigidity and hold performance even on high undulations. Autoclave molded carbon fiber is used for the backrest skeleton. The highest performance sports seat in terms of materials, structure and performance. It fits your body like it's sucking and supports your body like it's wrapped around you. From the moment you sit down, you can feel the height of another dimension.