Designed to cap over the top of outdoor flagpoles up to 5-1/2" diameter. Secures to your flagpole using three allen type set screws that keeps the truck firmly in place. These trucks are threaded on the top to accept our gold aluminum ball tops or our eagle ornaments. These trucks are designed to use with flagpoles with an external halyard. They are available in a stationary or revolving truck. The stationary truck does not rotate and the revolving truck revolves with whatever way your flag is blowing reducing tangling.