Flush Rail fitting kit. Prorack Smartfoot fitting kits are interchangeable and fit both through and flush styles. Thousands of fitting kits are available to plug into the Smartfoot system. All roof types are covered by Prorack Smartfoot Technology. Flush Rail fitting kit. Prorack Smartfoot fitting kits are interchangeable and fit both through and flush styles. Thousands of fitting kits are available to plug into the Smartfoot system. All roof types are covered by Prorack Smartfoot Technology. Prorack Smartfoot technology Flush Rail fit Designed to suit specific vehicle/s - find your car to get the right fitting kit