The High Grade Bodies / HB Series is made to fit the wheelbase of a typical 1/10 RC drift car. The wheelbase is 257mm to 260mm, so it can be easily installed on your existing RC drift chassis. The Real Grade Bodies / RB Series is a model that faithfully downsizes the wheel dimensions of the actual car to 1/10. This product is recommended for drivers who want to pursue even greater realism. Please use a chassis that allows for variable wheelbase.