RK Vortex Gld O-Ring Blk QA Chain and Sprocket Kit for HON CBR600RR 07-11 RK Chain Model: GB520XSO-112RK RK Chain Type: Gold O-Ring Vortex Front Sprocket: Steel 15 Tooth Vortex Rear Sprocket: Black Alum 42 Tooth Bike's stock Gearing: 16-42