They fit on the rad support to keep air from going over the rad. Boxing in your radiator ensures that your cooling system is operating as efficiently as possible. R Theory Rad support covers are made from light weight aluminum and are powder coated black or left in a brushed aluminum finish. Comes with all the stainless steel bolts and plastic spacers required to bolt it in.
But they are not only useful for increasing radiator efficiency, It's also cool bling to show off in the Tim Hortons parking lot! Also a great place to put tools when working in the engine bay.
Blue is now discontinued.