Spacer blocks are useful to obtain a level height between all of the crossbars on your vehicle. Simply place the spacers between the leg unit and the crossbar of your roof rack until all of the crossbars have been raised to an even level.
The Yakima Landing Pad 3 is the base rack solution for the Dodge Durango. The Landing Pad 3 attaches to the OEM factory rack tracks, replacing the factory crossbars, if it has them, and creates a dependable Yakima roof rack.