RK Vortex Gld MX Blk QA Chain and Sprocket Kit for HON CRF250R 04-09 RK Chain Model: GB520MXZ4-116RK RK Chain Type: Gold MX Vortex Front Sprocket: Steel 13 Tooth Vortex Rear Sprocket: Black Alum 52 Tooth Bike's Stock Gearing: 13-51