For models WITH or w/OUT in Bed Hitches and most side-mount fifth wheel hitches, Not fit for vehicles equipped with factory air susppension. RELIABLE PERFORMANCE – 24 hours air tightness test? 0.02MP, durable and safe to use, maximizing the load-carrying capacity and stability. Designed to relieve the pressure which usually placed on your vehicle’s leaf springs when your vehicle is carrying heavy loads. PRACTICAL INSTALLATION – The bolt-on installation requires no drilling or modification. Installation manual is available to download on the product page or you can contact our customer service to send it. PACKAGE INCLUDES – 2 x Heavy duty double bellow air Ride suspension bags, and all brackets & hardware for installing. Instructions are not included, please send us message if you need.