These high-strength, heavy duty aluminum ramps are designed to load particularly heavy machinery with a weight capacity of 20,000 pounds per axle. They work with rises between 36 inches and 42 inches, and can be used with standard trailers as well as step decks. The two-beam ramps feature extra wide, serrated rungs that provide maximum traction in the snow, rain, or heavy mud. The ramps attach to the trailer using a long pin and skid seats (sold separately) that are welded to the back ends of the trailer. Wall brackets are also available to allow users to drive loading equipment into basements. Both ends of the ramps are equipped with welded pin receiving tubes for bi-directional use.