Spacer blocks are useful to obtain a level height between all of the crossbars on your vehicle. Installation is a breeze - 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. Each spacer is 10mm high. This pack includes 2 spacers and 2 M6 x 45mm bolts.• Designed specifically to fit Rhino-Rack Vortex bars
• Provides one bar with a 10mm increase in height