Polini,have produced this reliable cast-iron kit for everyday use. Will work with the original carburettor although mainjet should be increased by aprox. 8-10%.Remarkable because of its massive bottom end punch, which makes it wheely addict's premier choice. Comes with gaskets, piston and cylinder-head Compatible with: - Aprilia: Area 51_S, Rally 50 LC_S, SR 50 Min.LC_S - Beta: Ark 50 LC_S - Malaguti: F12 LC_S, F15 Firefox_S - Mbk: Mach G 50 LC_S, Nitro 50_S - Yamaha: AEROX 50_S