This is the optional one-piece aluminium rear suspension holder that’s a direct replacement for the standard forward holders of the rear suspension. This holder is recommended to be use for more steering in high grip conditions only. The CNC machined aluminium lower rear suspension holder allows the suspension arms to be mounted independently from the diff bulkheads and is finished in orange.
#302050-O Xray T4 Aluminium Lower Rear Suspension Holder – orange
Source: Xray