Lose the bumps, chucks and jars. By adding an air bag at the hitch connection, you, your towing vehicle and the coach enjoy smooth, stable towing performance. The TrailAir (R) coupler's unique scissor action design acts as a buffer, cushioning the hitch area, protecting your 5th wheel trailer. The air bag absorbs the road shock. Upgrade to the TrailAir(R) Pin Box for an improved ride for your truck and your family, your coach and all the things that ride inside.