UMI's tubular lower control arms utilize our Roto-Joint technology for a bind free performance and quiet comfortable ride quality. The Roto-Joint design is a pivot ball lined with a greaseable delrin race designed to offer 28 degrees of total unrestricted movement, more than adequate for a bind free, low friction operation. The Roto-Joint design improves performance over the factory rubber and aftermarket polyurethane bushings by allowing the suspension to articulate correctly, and provide precision handling. The installed UMI Roto-Joint allows rear end free movement when high handling, auto cross or road race is a concern while still being a 100% streetable setup. The installed delrin race, which lines the spherical ball, absorbs shock and road noise for a quiet and smooth operation on any street or track driven vehicle. This control arm set features polyurethane bushings on one end and UMI's spherical Roto-Joint on the other end. This set-up is designed for street performance and street enthusiast. The polyurethane bushing end is designed to be bolted to the vehicle chassis side while the Roto-Joint attaches to the rear end side. Since the polyurethane bushings are softer they are designed to absorb more road noise and shock before it enters the passenger compartment of the vehicle. Both control arms feature the correct provisions for adding a stock or aftermarket sway bar. Sway bar holes are reinforced with a 0.120" wall thickness steel sleeve that is TIG welded and sanded into place. All bushing ends and Roto-Joints are greaseable and low maintenance making an excellent street setup for your cruiser!