The Trailair® Air Ride™ Pin Box acts as a buffer between the tow vehicle and RV, arresting the impact of road shock and stabilizing the towing performance. How? Simple — the unique scissor action allows the air bag to absorb road shock and vibration while the gas shock handles the rebound or bounce effect, giving RVers a better, smoother ride.CURT, a Lippert brand, offers a complete line of towing products and is the leading manufacturer of USA-made custom-fit trailer hitches. We offer the broadest selection of custom-fit receiver hitches for nearly every vehicle on the road today. With our extensive collection of towing accessories, from gooseneck, 5th wheel and weight distribution hitches to ball mounts, bike racks, pin boxes and much more, you can count on CURT to provide premium towing products that get you where you need to go!