The Drydock has a yframe design that creates a topofcar system for kayaks, canoes, and other long loads. Fits onto 2 receiver hitch with an antiwobble threaded hitch pin, for a solid base. Stabilizing straps included. Adjustable height to match your rooftop rack. Combines with a pair of towers or the outdoorsman 300 and a roundbar to make a topofvehicle system.