JT Sprockets JTSK7018 525Z1R Chain and 15 Front/42 Rear Tooth Sprocket Kit Fits: Ducati 944 Sport Turismo ST2 97-03 Kit Contains: 15 tooth Chromoly Front Sprocket; 42 tooth Steel Rear Sprocket; & JT 525Z1R-102 Link Chain SCM415 chromoly steel alloy is used for the front sprocket, and ultra-durable high carbon C49 steel for the rear sprocket JT Z1R Super Heavy Duty Chains are contructed with quad riveted pins for an extra strong rivet that resists powerful lateral forces on the extra thickness outer plates X-Ring seals are used for a better seal and produce less friction than conventional O-ring chains