The Roadmaster Active Suspension is a Heavy Duty coil spring that functions as sway bar, traction bar and helper spring. A uniquely designed, one of a kind product! Designed to attach to the rear leaf springs of any pick-up truck or van, the Roadmaster Active Suspension, converts the traditional "passive" spring into the more desirable "Active" suspension system. Is your truck sagging from a heavy load? Is your truck swaying more than you would like it to? Are you experiencing wheel hop as a result of axle wrap? We have got the product for you!