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: SR 50 04-Piag._S - Derbi: GP1 50 LC_S - Gilera: DNA 50 LC_S, Runner SP 50 -05_S, Runner SP 50 06-_S - Piaggio: NRG 50_S, ZIP SP 01-_S