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 PRO Additonal Fitment:1999-2000 SKI DOO BRP GRAND TOURING 7001999-1999 SKI DOO BRP MACH I2000-2000 SKI DOO BRP MACH 12001-2001 SKI DOO BRP MACH Z STANDARD1999-2000 SKI DOO BRP FORMULA III 8001999-2001 SKI DOO BRP GRAND TOURING SE1999-1999 SKI DOO BRP FORMULA III 7001999-1999 SKI DOO BRP FORMULA III 6002001-2003 SKI DOO BRP MACH Z TECH PLUS2000-2000 SKI DOO BRP FORMULA lll 7001999-2000 SKI DOO BRP MACH Z