The next generation premium fifth wheel pin boxes! Acts as a buffer between the tow vehicle and the trailer, minimizing the negative impact of vertical shock and longitudinal chucking. Improves ride and relieves road stress on trailer's frame, cabinets, mechanicals and electronics. Reduced vibrations saves furniture, TVs, computers, dishes, glassware and other fragile items. Driver's and passengers benefit from reduced road fatigue. Unique streamlined design is engineered with a 21,000 lb. rating. Allows tuning of the air spring to optimize the performance of each truck and trailer combination. No assembly required and easy to install using existing holes and hardware. This item is a special order part from Reese and may take a while longer to receive.