Bikeman STM Rage 4 Primary Clutch Pro RSKU: ST 2001315 Rage 6: Single Stage with Heavy duty bearing. Use for High HP applications. Rage 4: This clutch also incorporates a lager diameter 2 way bearing design for longer lifespan through use and smooth gear selection. Stock replacement style clutch fits under stock clutch housing and uses stock bolt Uses stock or stock replacement style belts Can be used with the stock or STM billet Tuner secondary clutch. Uses PS style springs with no spacer