RK Vortex O-Ring Blk QA Chain and Sprocket Kit for YAM YZF-R6 06-13 RK Chain Model: 520XSO-114 RK Chain Type: Gun Metal O-Ring Vortex Front Sprocket: Steel 15 Tooth Vortex Rear Sprocket: Black Alum 45 Tooth Bike's stock Gearing: 16-45