RK Vortex O-Ring Alu QA Chain and Sprocket Kit for HON CBR600F4 01-06 RK Chain Model: 520XSO-108RK RK Chain Type: Gun Metal O-Ring Vortex Front Sprocket: Steel 15 Tooth Vortex Rear Sprocket: Aluminum 46 Tooth Bike's Stock Gearing: 16-46