The Rokkaku or 'Rok' for short is a design of 'ancient' Japanese origin. Nobody knows exactly how old the design is, but it is at least hundreds of years old. It is very efficient and is a favorite for lifting payloads reliably. It is a favorite for KAP because it does not require a tail for stability, has an angle of attack or AoA that is simple to adjust to get it just right for the wind, does not collapse and sink out in lulls as soft kites do, and is easy to set-up.