Hellwig Pro Series Rear Helper Spring is a set of secondary leaf springs that work with OEM leaf springs and support extra loads. It is made for heavy hauling, work-truck use, or pulling 5th-wheel RV trailers. To install on full-size pick-up trucks and vans it requires mounting hardware (where applicable) to accommodate 2 1/2 or 3 wide leaf springs. Its load carrying capacity is up to 2500 lbs. Hellwig Pro Series Rear Helper Spring prevents leaf spring from distortion due to continuous load compression. It manages proper rear ride height. When you are towing, Hellwig Pro Series Rear Helper Spring reduces bouncing at the rear side of your vehicle. It stabilizes helper springs in reverse or rebound mode.