Circuit Sports 350Z/G35 adjustable front upper control arms are direct replacements of the factory upper A arms. These arms are designed to resists flexing with its tubular design to withstand the stress under load. They include a sliding ball joint allowing enthusiast to fully adjust the front negative camber to carefully tune the vehicle to increase steering efforts, improvements in high-speed stability, and cornering effectiveness. The new FUCA uses a Teflon spherical Heim joint with steel spacers to replace stock rubber bushings to guarantee long lasting quality and allow your suspension to move freely yet precisely to ensure controlled suspension movement that you would require in competitive driving.