Carlisle Ultimax 3 has evolved into Ultimax PRO. Thicker cross section so more surface area is in contact with clutch. New cog design dissipates heat and aids flexibility Runs cooler for better performance. Run cool, run long & run fast with Ultimax PROAdditonal Fitment:1983-1983 POLARIS CUTLASS SS1990-1990 POLARIS INDY SPORT GT1983-1985 POLARIS SS1988-1990 POLARIS SPRINT ES1987-1987 POLARIS SPRINT1985-1985 POLARIS LONGTRAK1986-1987 POLARIS LONGTRAK 4401987-1987 POLARIS SPORT INDY1986-1986 POLARIS SPRINT 340 E/S1988-1989 POLARIS INDY SPORT