More air, more mixture, more power for the new Big Evolution engine lamellar valve. The valve, vulcanized with selected rubber compound specifically to withstand petrol, mixtures and higher operating temperatures, has carbon slats with a thickness of 0.3 mm. The fixing plate is made from anodized aluminum tank. It can be mounted on PIAGGIO after processing the crankcases and assembly with 24, 26 or 28 mm power plants is recommended.