"Quickly and easily store heavy duty loading ramps below a step deck tractor trailer deck with clamp-on ramp hanger brackets from Discount Ramps. Each ramp hanger bracket clamps to the trailer underside and no drilling is required for install. Designed for tractor trailers without knee braces. The lockable design enables brackets to be secured with a pad lock to help prevent theft. Installation is quick with only a 3/4"" wrench and measuring tape. Heavy duty all-aluminum construction Made in the USA."