Arnott's premium rear shock for GM vehicles equipped with air-assisted suspensions is an ideal replacement for a failing rear shock. This top-of-the-line shock, engineered in the USA, delivers control, stability, performance, and comfort. Arnott's new aftermarket shock connects to the vehicle's auto-leveling system with no modifications and includes a bypass resistor to turn off dashboard warning lights for the auto-damping control unit. These rear shocks should be replaced in pairs. Not applicable for vehicles w/Magneride suspension.