This kit includes (1) set of UMI Boxed lower control arms and (1) set of UMI on-car adjustable upper control arms, "Ultimate Arms". Both items are direct replacements of the OEM set up adding strength, ride improvement and most importantly, rear end adjustment. The lower control arms feature grease-able Energy Suspension polyurethane bushings, reinforced sway bar holes to accept all sway bars and brilliant powder coat. The upper "Ultimate Arms" feature on-car adjustability using right and left hand threads, 4140 high strength Chrome Moly adjuster and a QA1 PTFE lined spherical rod end. The upper control arms give you best and easiest way to adjust pinion angle for suspension tuning.