Rear shock towers are redesigned to allow for the Horizontal Split Bulkheads (HS), and have denser top shock mount positions to get more accurate set-up corrections. A corner shock tower features additional roll center jobs even for more fine set-up modification also extra wing mounting jobs. Back shock towers are machined from premium-grade 3.5 mm graphite as they are lightweight & strong, with numerous shock positions and roll center adjustment roles Fits XB4'21
