This system includes :ront Lower Arm-2PCSRear Lower Arm-2PCSStainless Steel Round Head Screw 3x16-4PCSOriginal title / Part No:AR330520+AR330521Support the chassis and support the front&rear knuckleMajor benefits of updating for this part/product :1. Aluminum 6061 T6 material created for better energy, threshold and more elastic. The delrin collars are placed to the arms to minimize the play and fortify the fitting.2.Compare to your original design, the product has a fashionable hollow design.3. Numerous placement holes for users to regulate the angle associated with dampers.