Reese 5AB-E1621-16K Reese Elite Airborne Extended 12" Wide Air Ride Pin Box Air bag is located on the top of the pin box instead of the bottom, making it easier for the end user to make adjustments Measures true to the Lippert 1621 pin box Reduces chucking by 60% and vertical shock by 44% Airline comes standard for easy air fill One-piece body design