These are reed valves designed with flow corner and with calculed capacity section. The petals are made of a material composed of karbonit and carbon. They are manufactured with advanced production processes and with the use of raw materials carefully selected. These reed valves are designed for racing engines and they have been tested directly on race tracks. Compatible with: - Aprilia: Area 51_S, Rally 50 AC_S, Rally 50 LC_S, Scarabeo 50 Min.AC_S, Sonic 50 AC_S, Sonic 50 LC_S, SR 50 Min.LC_S - Beta: Ark 50 AC_S, Ark 50 LC_S - Malaguti: Centro 50 AC_S, F10_S, F12 AC_S, F12 LC_S, F15 Firefox_S - Mbk: Mach G 50 AC_S, Mach G 50 LC_S, Nitro 50_S, Ovetto_S - Yamaha: AEROX 50_S