Right back shock towers are redesigned permitting the Horizontal separate Bulkheads (HS), while having denser top shock mount functions to obtain additional accurate set-up alterations. A large part shock tower features extra roll center jobs even for more fine set-up modification in addition additional wing mounting functions. Right back shock towers are machined from premium-grade 3.5 mm graphite and they're lightweight & strong, with many shock jobs and roll center modification functions Fits XB4'21