The two shoes clutch with adjustable compressive springs comes from the experience of the scooter and off-road races. A considerable improvement is given by a new adjustment system of the spring preloading; the register has a threaded nut that lets you adjust the preloading at the millimeter and choose the clutch bite you like Compatible with: - Aprilia: Scarabeo 50 Piaggio_S, SR 50 04-Piag._S - Derbi: GP1 50 LC_S, GPR 50 06-_S, GPR 50_S - Gilera: DNA 50 LC_S, Runner SP 50 -05_S, Runner SP 50 06-_S, Stalker 50 AC_S, Thyphoon 50 AC_S - Piaggio: Beverly 50 06-_S, Liberty 50_S, NRG 50_S, Vespa 50 ET2_S, ZIP SP 01-_S