UMIs adjustable upper a-arms are designed to excel in Pro-Touring, road race, auto-x and hot street corner carving. The race quality rod ends provide shim-free camber and caster adjustment along with ultimate smooth travel. This arm features a relocated ball joint pad to increase caster and improve stability and steering feel as well as a shortened cross shaft to ball joint distance. We recommend the 4056 arm for all racing applications. Arm must be used with tall spindles when using standard height ball joints. 100% manufactured, tested and raced out of Philipsburg, PA USA.