All upper tubular and lower boxed trailing arms use polyurethane bushings on both ends, while upper adjustable and lower tubular trailing arms use a spherical ball or rod end assembly on the chassis end to eliminate bushing bind, allowing the suspension to move smoother for better control. This keeps the tires planted firmly on the ground for improved traction and a more predictable, better handling car. Trailing arms are powder-coated gloss black for a long lasting finish. Adjustable Tubular Lower Trailing Arms are offered in both aluminum and steel. These arms are the ultimate in weight savings and adjustability, and they feature QA1's premium self-sealing and self-lubricating X Series (heat treated chromoly steel) or A Series (aircraft aluminum) rod ends. Kits include (2) lower control arms with rod ends and jam nuts.