Rêve D RDX R-Tune Spring - All Set w/ BoxRve D (#D1 SS1AS) RDX R Tune Spring All Set w Box Feature: For: Universal Parts Introducing the new R tune spring specially tuned for RDX car kit, which uses the amazing SWO material that has been proven in the R tune series! By adopting a new SWO material and making it easier to induce initial subduction even at higher spring rates gives a strong kicking feeling and control performance are realized at a high level. The spring length is 23mm, which is