Can go on the rear of any RV–straight or contoured Rugged construction 250 lb maximum Do not exceed the Maximum Weigh Capacity of 250 lbs. Mount the ladder to the frame or substructure of the RV only. Installation includes drilling and cutting. Always exercise caution and use proper safety equipment, including safety glasses, during installation and use of tools. Seal all the holes drilled into the RV with an RV-type weatherproof sealant to prevent leakage.