Aluminum back Lower Suspension Holder REAR for semi-split bulkheads offer an expanded array of set-up modifications. The aluminum suspension holders feature built-in Suspension Settings™ (I.S.S.) which allows for quick & easy suspension system geometry environment. Utilizing eccentric suspension system bushings inserted into aluminum suspension holders – plus additional suspension shims – the XB8 suspension geometry is completely adjusted in only seconds. Machined from premium Swiss 7075 T6 aluminum and black coated.