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: SR 125/150_S, SR 50 04-Piag._S - Derbi: GP1 50 LC_S - Gilera: DNA 50 LC_S, Runner 125/180_S, Runner SP 50 -05_S, Runner SP 50 06-_S, Stalker 50 AC_S, Thyphoon 125 2T_S, Thyphoon 50 AC_S, Typhoon 125_S - Piaggio: NRG 50_S, Vespa 50 ET2_S, Zip 50 2000_S, ZIP SP 01-_S