Valve operating design
In the 1960s Ducati introduced the Desmo valve, and almost every other company had common valve springs. This company introduced another way to close the valve. It was state of the art and allowed the engine to rev to 10,000 RPM when all other engines of that time only reved to 6,000 RPM.
What year, make, and model was it. What type of valve return mechanism did they use?