The UMI bolt-in rear coilover kit provides comprehensive adjustments for ride height, spring rate, and damping, in addition to enabling trailing arm adjustments for precise calibration of the instant center. This kit is equipped with a fortified upper mount, specifically designed to accommodate a 2-1/2” racing coilover with a double-shear configuration. The lower brackets, engineered through Finite Element Analysis (FEA), are reinforced and are designed to be bolted directly onto the existing Quick Performance rear lower control arm mounts. These brackets also feature an adjustment mechanism for trailing arm height, facilitating the tuning of the instant center location using the 3 available positions. This product is manufactured and tested in Philipsburg, Pennsylvania, utilizing materials sourced from the United States.We advise that the brackets be installed initially and that measurements be taken from center to center at ride height to guarantee the precise identification of shock part numbers. Regarding compatibility, this kit is designed for direct installation with a Quick Performance rear.