RK Vortex Gld O-Ring Blk QA Chain and Sprocket Kit ZX600JKM ZX-6R 98-08 / 03-04 RK Chain Model: GB520XSO-108 RK Chain Type: Gold O-Ring Vortex Front Sprocket: Steel 14 Tooth Vortex Rear Sprocket: Steel 40 Tooth Bike's Stock Gearing: 15-40