RK chain and sprocket kits are the perfect drive maintenance kit for your bike including a strong and durable 13T front and 50T rear steel sprocket constructed from SCM420 chromoly steel alloy (front) & C45 high carbon steel with an electroplated Zinc finish (rear) paired with a high-quality RX-ring RK chain this kit has everything you need to replace your old warped and stretched chain and sprockets. The perfect alternative to expensive OEM replacements while designed to meet and exceed OEM specifications. Supplied in presentable packaging with a carry handle for convenient transportation. About the Chain: With a pre-stressed and pre-stretched process applied to maximize the life of the chain. KRX series chains are equipped with the unique RX-ring technology by doubling the sealing surfaces the seals seal significantly better against water and dirt resulting in a 25% increase in life compared with an O-ring chain. Perfect for those seeking a long life chain in all riding environments. Fits: Honda CRF250R 2004 2008-2013 2015-2017 CRF250X 2004-2007 2009-2018