Sulastic Rubber spring shackles replace the old leaf spring shackle located between the leaf spring and the leaf spring mount known as the hanger. Sulastic's large rubber spring reduces vibration by absorbing the suspension deflection and smoothing out the leaf spring's oscillation while not affecting the load or tow capacity due to the stop member which is reached when the load is on the vehicle. This product is sold per set per axle. This sulastic is for the rear axle.